In EP049, he and Komajiro dress as Santa Claus and help deliver presents for children. For the first time in the anime, Komasan gets angry with Komajiro. He tells him that as a Santa, he should not have used a taxi to return to him. Komajiro cries, heartbroken at having disappointed his brother, but explains he took a taxi because if he walked, he would have been unable to give Komasan a Christmas present: a small green sling pouch. Komasan thanks his brother and they enjoy the rest of Christmas.
In EP071, he makes a cameo and eats a boyfriend's ice cream.
In EP073, Irewig makes him ticked off. However, unlike Happierre, he solves his ticked off problems by cleaning all the gum of the street. He also forces, Nate, Whisper, Jibanyan, and even Irewig to help him build birdhouses. In the end, Irewig gives Nate his medal and Komasan rejoices with his new bird friends.
In EP082, Minochi makes him, Komajiro, and several other Yo-kai jealous at Nate because he was not summoned when they wanted to be. In the end, none of the formerly jealous Yo-kai knew why they were all near Nate, so Komasan asks him. Nate simply says: "All this attention has me tired . . ."
In EP091, he and Komajiro host the Yo-kai Red & White Song Battle. He chooses the Red team as the winner because Jibanyan was happy while Whisper was not.
In EP095-EP097, EP099, and EP101-EP103, Komasan plays Komashiro in "Dog of the North Star," the Yo-kai parody of "Punch of the North Star." He accompanies Whisper and defeats enemies like Sproink, Roughraff, and Thornyan.
In EP103, Komashiro has his final boss battle against King Nya (Jibanyan). As they continuously punch each other rapidly, a tornado surrounds them. When it disappears, only one Yo-kai stood, but it was neither Komashiro nor King Nya, no, it was Jibakoma. This shocks Whisper and King Nya's horse, but a light from the seemingly endless smoke clouds shines on the fused Jibanyan and Komasan Yo-kai, and the series ultimately ends with Jibakoma saying: "For once in my life, I regret nothing."
In EP107, he sobs because he thinks Whisper really hates him and all other Yo-kai, much to the bewilderment of Nate and Whisper.
In EP119, he and Komajiro watch the Yo-1 Grand Prix in a hot-air balloon powered by Blazion's head and they root for Nate's team. When it came down to a close call scenario, Komasan's chooses Nate, Whisper, and Jibanyan as the winners because they beat Inaho and USApyon by 1 centimeter.
In EP120, he and Komajiro, as Sangokushi commanders, recruit Venoct. Venoct plans to slaughter a tiger, but Komasan interferes and proves that the ferocious animal is actually friendly. Komasan's new tiger friend playfully bites Venoct, thus delighting Komasan, embarrassing Komajiro, and annoying Venoct.
In EP130, he makes a Dream Land cameo and wins the ice cream prize.
In EP131, he meets Jerry, who gets his medal via tickling.
Komasan's younger brother, whom he loves very much, and strives to look cool and street-savvy toward. When Komajiro seems to take on the ways of the city much more quickly than he does, Komasan grows worried and possibly jealous. The pair live together in a small house and often go on small adventures with one another. Despite being younger, Komajiro is smarter than Komasan.
Ever since he first met Nate and Whisper, they have been friends.
It is unknown when Komasan first met Jibanyan. It is shown however that Komasan looks up to Jibanyan's power a bit wanting to fuse with him and become Jibakoma. In Yo-kai Sangokushi, he and Jibanyan go to the library and try and find the "Sangokushi" book, he very tolerates of Jibanyan.
Inaho said she prefers Komasan's and Komajiro's cuteness to USApyon's moodiness, much to USApyon's annoyance, to the point he activated Vader mode on her. Komasan says "what fun" in response.
The two of them don't know each other too well, but they get along fine. Unlike most characters, Komasan is not scared of Vader mode, instead he thinks it's fun.
Komasan writes and sends Koma Mom letters about how his life in the city is going. She appears in the second movie when Komasan and Komajiro go and visit her. Koma Mom tells Komasan and Komajiro that they have a new baby brother, Komasaburo.
Komasan briefly falls in love with a manga artist at a local coffee shop and is distraught by the fact that they can't be together due to coming from different worlds. He disguises himself as a human to befriend her and and aids her when she loses her manuscript on the sidewalk. Later, he finds her disconsolate in the shop, and she explains that her publisher rejected her Yo-kai comic since no one believes in Yo-Kai anymore.
As their hands briefly touch, Komasan realizes that he encountered the same girl when she was much younger; she had passed him by with her grandmother while holding a cone of soft serve ice cream, which caught his attention. Mako admits that the experience was what inspired her to draw Yo-Kai comics in the first place, but has now become discouraged by constant rejection. Bravely, Komasan reveals himself, inspiring the girl to draw her next comic based on him. Komasan purchases her comic, but is disappointed to find that she portrayed him as a towering, ferocious monster. Ultimately, Komasan admits that he doesn't regret talking to her despite the relationship not working out, and gained a liking for coffee (which he previously found disgusting).