Howard and Randy are best friends, and although they have arguments, they always forgive each other. Both have been friends for a long time, such as playing with ninja sword toys when they were younger. They share many interests, like video games and music. While at first, Howard is 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, in "Evil Spirit Week", and truly means his apologizes when he actually gives them.It doesn't always come across, but Howard deeply cares for his best friend's welfare, even after feeling hurt by him, going as far as to save him in "30 Seconds to Math" and "Nukid on the Block", and trying to cheer him up by making him gravy fries in "Bash Johnson: 11th Grade Ninja", although Randy gets sick from the substitube used to replace the gravy. Sometimes, he also points out when Randy is doing something wrong and sees the situation more than his most-of-the-time more logical friend. For example, he tells Randy that giving up being the Ninja because people don't want him is ridiculous is "Lucius O'Thunderpunch". While things can get rough between them, Howard is proud of Randy and knows how to work with him when they need to be a team. 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. They both argue with each other a lot, not afraid to use cutting remarks or insults. 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, he cares for her enough to be horrified and disgusted when NomiRandy flirts with her in "Shloomp! There It Is!" and when Randy admits he finds some things about Heidi attractive in "Welcome Back Catfish". Gossip Boy", when McFist overhears him admit that he knows the Ninja's secret identity and captures him to discover the truth, and in "House of 1,000 Boogers", when he and Randy sneak into the Bash Splash and he tells McFist that Bash isn't a jerk. Howard's dad's business was bought out by McFist, and he was afraid to let Randy know in "Silent Punch, Deadly Punch". McFist and Howard didn't interact back then. 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.
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.Attack of the Killer Potatoes", just like Randy, and finds him annoying and bothersome. In "Monster Dump" he is going to leave Bucky, who got caught by the blob monster, behind. In "The Ninja Supremacy", while being the Ninja, Howard is annoyed when Bucky notices that the Ninja seems different and pushes his body off of him when they land on the ground. Although pleased that Bucky supports him over Randy in "Sorcerer in Love 2: The Sorceress's Revenge", he comments that Bucky has sweaty hands. He becomes casual friends with Bucky and Bucky's friends while Randy is busy ninja-ing in "True Bromance", although this falls apart when Randy becomes jealous and traps Howard's new pals on the roof of Norrisville High.
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.
Howard doesn't care much for Julian, thinking that he is a weirdo. In "The Tale of the Golden Doctor's Note", Howard admits that he know "Lord Creepy" was a fraud when Julian admits that he doesn't find death cool, and he abandons the terrified Julian so that he can find the doctor's notes with Randy. While bond a bit with Julian in "Der Monster Klub", Howard still doesn't seem to think highly of him. 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. In "Ball's Well That Friends Well". Howard refers to Julian as "annoying Julian".
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".
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".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 its convienent 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.