Relationships
Randy Cunningham[]

Howard and Randy are best friends, and although they have arguments over the most trivial matters, they always forgive each other. Both have been friends for a long time since they were three years old, such as playing with ninja sword toys when they were younger. They share many interests, like video games and music. While at first, Howard was excited when he found out Randy was the Ninja, he eventually comes to feel like it is ruining any chance of them having fun or earning popularity. It also annoys him that Randy has to NNS (standing for Ninja No-Show) constantly, and fight the evil at hand before other things that Howard finds important, like their grades and video games, can be achieved.
Unlike some best friends to heroes, Howard doesn't always support Randy, and shows little compassion, mercy, or understanding towards Randy's issues as the Ninja. Whenever a problem occurs, Howard usually tries to blame Randy for problems, even when it's obviously his own fault, like in "Gossip Boy". Other times, Howard will abuse the friendship for his own benefit, whether it be lying to Randy about being late just to buy him some food, or getting Randy to use his powers to fix a problem. Even when Randy is trying to help him, Howard doesn't always appreciate it, especially in "Escape from Detention Island". When Randy messes up, Howard is a lot less likely to genuinely forgive him than vice versa. But he still honestly thanks Randy for saving him, albeit Randy's fault causing the situation in the first place, such as in "Evil Spirit Week", and truly means his apologies when he actually gives them.
Also, Howard is known to be extremely jealous and insecure in his friendship with Randy; whenever Randy shows good rapport or just interacting with another person, he will immediately get envious and rude to the person his own best friend is interacting with, even attempting to dissuade Randy from doing the right thing for the person, or downright sabotaging their interactions. For example, he has pushed Randy into not helping Julian in both "The Tale of the Golden Doctor's Note" and "Snow-Klahoma!" (which he actually succeeded in the latter episode), and he also gets incredibly begrudging when Randy is being very friendly with Theresa in "Night of the Living McFizzles" and "The Brawn Also Rises". He even goes as far as to interrupt Randy who wants to dance with Theresa in "Sorcerer in Love", causing him and Randy to argue, and thus effectively ruining Theresa's mood.

Heidi Weinerman[]

Howard is not very fond of his older sister, who is also rather uncaring towards his well-being. Her popularity and success at everything extremely frustrates him. They both argue with each other a lot, not afraid to use cutting remarks or insults.
In "30 Seconds to Math", he wants to beat her at the Battle of the Bands, and in "Grave Puncher: The Movie", he laughs at her when she fell over while practicing for her drivers' test. Howard admits he always expected his sister was a dog when she gets stanked in "Sorcerer in Love 2: The Sorceress's Revenge", while she threatens him with blackmail, like in "So U Think U Can Stank".
However, despite their unhealthy sibling rivalry, he cares for her enough to be horrified and disgusted when NomiRandy flirts with her in "Shloomp! There It Is!" that anyone and when Randy admits he finds some things about Heidi attractive in "Welcome Back Catfish", although also because he justifiably believes anyone who likes someone as superficial as Heidi has low romance standards.
The only instance they appear to care for each other even just a little is in "Living in Shooblivion", where they bother hosting Scarf Center together, as they are able to benefit from each other.
Mort Weinerman[]

Howard doesn't have too much care for his father, always demanding Mort and often disrespects him, due to Mort being too lax on parenting him. He also only likes Mort just a little (revealed by himself in "Club Ninja-dise"). He had no qualms on lying to Mort in "Mort-al Combat" even if he got punished for cleaning up his house afterwards, although he also got disciplined by Mort for pretending to be sick in "Randy Cunningham's Day Off".
Despite his usual apathy for his father, he does share his disgusting habits with Mort, shown in "On the Poolfront". He also briefly worked with Mort in "Escape from Scrap City" to save Randy and McFist.
Hannibal McFist[]
Howard, just like Randy, likes buying McFist's products, and is shocked to find out that McFist is evil. Unlike Randy, who actively hates McFist as a person, Howard continues considering McFist as a businessman who can still give him materialistic benefits through the McFist Industries products. Sometimes, Howard will support McFist over Randy due to being benefitted by what McFist entices him for.
His only few interactions with McFist happen in "Gossip Boy", when McFist overhears him admit that he knows the Ninja's secret
Howard's dad's business was bought out by McFist, and he was afraid to let Randy know in "Silent Punch, Deadly Punch", although McFist and Howard didn't interact back then. However, this also evidences that Howard is aware that McFist is a threat to his best friend, and therefore will still mostly prioritize Randy over McFist.
In "McSatchle", Randy and Howard got jobs at McFist's movie theater and McFist was reminded of himself by how Howard treated others. McFist then gave Howard a promotion to manager but Howard was eventually fired for socializing with the Ninja.
He also voluntarily gave McFist the plan to send a robot to attack the school in "Randy Cunningham's Day Off", just to force Randy to come to school, regardless of the prospect of McFist's subsequent actions endangering others.
Willem Viceroy III[]

Howard thinks that Viceroy has style, and dresses up as him for Halloween. He has only met Viceroy a few times, the first time in "Gossip Boy", when he is captured and Viceroy planned to put a mind reader on him, and the second time in "Dawn of the Driscoll", when Viceroy is impressed with his costume. The third time, in "Rise of the Planet of the Robo-Apes", they hang out and bond until McFist forces Viceroy away. The fourth time "Weinerman Tested, Cunningham Approved", he is given a pair of new McPeepers by Viceroy, who temporarily recruited him as a test subject, so both him and Viceroy are briefly on friendly terms afterwards.
Bucky Hensletter[]

Bash Johnson[]

Theresa Fowler[]

Howard and Theresa are classmates who do not interact much, but seem to get along alright, though his behavior can occasionally be off-putting to Theresa and he frequently gets very envious of her being good friends with Randy. He is jealous when Randy convinces both Theresa and Debbie that he isn't afraid of anything, and Theresa gives him her McFizzles to make him stop crying in "Night of the Living McFizzles". Like the rest of the school, he considers her to be an uncool student, initially not wanting to be sitting at her table in "Der Monster Klub". When Randy and Theresa briefly touch hands and while with the Klub, Howard looks very amused by it, showing that he is very aware that both sides like each other a lot.
Despite being aware of Randy and Theresa's affection for one another, Howard doesn't care too much about it, and wants to hog Randy's chance that's meant for Randy to be with Theresa. For example, he thinks The
However, in his fantasy during "To Smell and Back", he does picture Theresa as strong and capable against the Intraterrestrials, indicating that he is aware that Theresa isn't weak or defenseless.
Debbie Kang[]
Howard and Debbie noticably do not get along with each other. During "Viva El Nomicon", he and Randy disagree with Debbie when she tells them they aren't speaking Spanish, which proves to be true afterwards. Later, trying to get Debbie to help the Ninja defeat the Mexican Death Bear, he begrudgingly admits that her Spanish is much better than his, although she wasn't listening to him. He is furious at Randy in "Night of the Living McFizzles" when Theresa and then Debbie hold Randy's hand and believe that he isn't scared. His displeasure with Debbie continues in "All the Juice That's Fish to Swim" because he is angry with all the things he enjoys that she has ruined with her reporting.
In To Smell and Back, however, he does fantasize about Debbie admiring him in his own improvised story. This either implies he thinks he is irresistible to ladies, or he does secretly likes her without her knowledge.
Julian[]
Howard doesn't care much for Julian, thinking that he is a weirdo. In "The Tale of the Golden Doctor's Note", Howard
Not even wanting to go Julian's birthday except for free birthday cake, he doesn't have any issues with insulting Julian's lack of skills as a magician in "Julian's Birthday Surprise", having Randy volunteer to apologize for him instead of himself doing it. He also is the one responsible for dissuading Randy from helping Julian in "Snow-Klahoma!" in the first place.
In "Ball's Well That Friends Well", while Randy as the Ninja is trying to help Julian, Howard still refers to Julian as "annoying Julian", but he does briefly agree with Julian when not wanting to be swallowed by the Portal Beast.
Morgan[]

Howard admits that he likes Morgan and thinks she is feisty before sending the Dancing Fish and her offstage in "So U Think U Can Stank". She, in return, tells him to get off the stage when he and Randy are forced to perform as punishment from Heidi. He is pleased to see her on the island in "Escape from Detention Island". From his reaction, it can be assumed that he might have a crush on her. He checks her out in "Wave Slayers", and he's annoyed when she says she'd date Jacques in "Shoob Tube". It appears that he either doesn't know Morgan finds him annoying, or just deliberately continues flirting with her despite knowing her disdain for him.
Mac Antfee[]

Howard thinks that Mac Antfee is the coolest ninja he had ever met, upsetting Randy in the process, in "Ninja Camp". He even follows Mac's example, up until the point where he discovers that Mac plans on destroying the ninja. From that point on, it can be assumed that Mac is also his enemy. He is glad that Mac Antfee reformed in "Enter the Nomicon".
Doug[]

Out of all the known students in NHS, Howard has the most burning intense hatred for Doug. In order to vent his disdain at Doug, Howard will often go out of his way to insult, humiliate, or even hurt him. Examples of Howard hating Doug included:
- Howard puts his empty bowl of chili into Doug's backpack in "Sword Quest."
- While wearing the school's mascot outfit in "The McHugger Games," Doug gets shot with a laser by the I.D. Bot, which Howard is holding, and Howard shows no concern to have shot Doug at all.
- The Ninja throws a ninja ring at the Prankzooka robot in "Pranks for Nothing," but the robot transforms it into an apple, which heads back towards Randy. Randy dodges, and Doug, who was standing behind him, gets hit with it. Howard walks over to laugh at him.
- In Howard's story in "To Smell and Back," Doug is turned to stone, which horrifies Mr. Bannister until he sees that it is Doug; Howard deliberately smashes the stone Doug to fragments (presumably fatally).
- In "The Fresh Principal of Norrisville High," what convinces Howard that the virtual Norrisville High can't be real is the fact that he speaks politely to Doug.
- In "Let the Wonk One In", Howard immediately throws Doug away after Doug is reverted back to normal.
- In "The Three Mascot-teers", Howard has no remorse when Doug is humiliated for being the carp mascot and later also laughs at Doug for falling over in the boys' changing room.
Dave[]
In "So U Think U Can Stank", Howard sent Dave off the stage, which ended up getting Dave stanked. In "Der Monster Klub " Howard does not want to be seen sitting at Dave's table, declaring him to be a weirdo. But in "Secret Stache", Howard and Dave are seen talking to each other, probably meaning that they're friends, or at least get along when it's convenient for Howard. They hang out some more as casual friends with Bucky and Pradeep in "True Bromance", albeit briefly as Randy's envy causes problems.
Juggo[]
Howard normally lacks respect for Juggo, whom he considers to be a peculiar weirdo. In "So U Think U Can Stank", he deliberately denigrated Juggo during the Norrisville High Talent Show, which led to Juggo being stanked. He also found Juggo to be an unpopular weirdo, as seen in "Der Monster Klub".
Pradeep[]
Howard normally doesn't interact with Pradeep too much, although he admittedly doesn't have too much of a high opinion for Pradeep, whom he considers to be a run-of-the mill band geek. They hang out some more as casual friends with Bucky and Dave in "True Bromance", albeit briefly as Randy's envy causes problems.
Brent[]
In "Sword Quest", Howard became Brent's enemy, due to Brent prematurely assuming that S. Ward Smith has chosen Howard over him, leading to Brent being stanked. Brent is also justifiably angry at Howard in "Shloomp! There It Is!", when Howard dumps Randy's lunch onto his lap. However, they mostly either don't interact often with each other, and/or Brent can tolerate Howard as long as Howard doesn't do anything that annoys him.
Brawn Brickwall[]
Prior to "The Brawn Also Rises", Howard wasn't aware of Brawn Brickwall. However, when meeting Brawn, Howard considered Brawn to be a showboat and a fraud, even though he was also being a fraud himself. He then provoked Brawn after exposing Brawn publicly, and was very reluctant to apologize publicly himself in order to destank Brawn even when Randy forced him to do so.