Keisuke Naoto is a recurring character of the psychological horror magical girl manga/anime, Magical Girl Site. He is the store's cashier who secretly works for the loan sharks of Nijimi Anazawa's family.
He has no reason to exist, only because the author of that series probably wanted to add more male characters and not introduced a lot of females.
He is a very unnecessary addition to the series and has no purpose to the greater narrative of the story.
According to Aya's brother, Kaname, Keisuke is described to be "an epitome of trashiness' who is "quite naive lazy and aggressive".
He's your stereotypical fanboy of a Pop star idol, Nijimi Anazawa. But, he is obsessed with her, making him nearly a pedophile in which Nijimi is 14 years old.
Similar to Aya, Keisuke comes across like a sore loser with his life practically revolved around falling in love with Nijimi. But, when he realized Nijimi took a break as a pop singer, Keisuke fainted and crying, only for him to be driven to suicide because of that incident, and Kaname saved him.
He was even naive due to wanting to be friends with Kaname even there were signs of him showing his true nature.
He is much of a lazy store cashier since he doesn't bother to work hard to pay back his debts with the loan sharks of Nijimi's family.
Like Kaname, He is shown to be aggressive when someone interrupted him while he was watching Nijimi's Dog Play stage.
He barely has serves no purpose to the greater narrative to the story, but only exists to give Kaname some dramatic tension surrounding his stress relieving.
He even spends most of the majority doing absolutely nothing in this story other than filler.
After learning Kaname met Nijimi and thought he corrupted his angel, Keisuke went on to use a kitchen knife to kill Kaname. However, he ended up killing himself when Kaname used Nijimi's mind-controlling panties to forced him to do it.
He is outright terrible as a attempted murderer whenever Nijimi was in an affair with someone.
He lacks any more character development since chapters 7-35, and episodes 3-8.
He does not associate with Aya and the magical girls, and he's just self-inserted throughout the series and is a complete stranger.
His voice acting is good.
His character design is well-made and honestly cute.
At least despite her obsession with Nijimi, he is not a pedophile and wasn't shown to do juvinile things.
Since being like a sore loser, he is not at least evil at all, and he has sympathy.
He didn't kill Kaname (who uses Nijimi's panties to control people), which would make him nearly a muderer.
When Aya went back in time to prevent other girls from misfortune, thus he is no longer driven to suicide by Kaname's mind-controlling, no longer worked with Nijimi's family's loan sharks (who are arrested in the new timeline) and was engaged with his girlfriend, who moved away in the original timeline.
In the apple chapter of the DVD release of the anime adaption of Magical Girl Site, he was revealed to have a mother, who is exclusive to this chapter.
His hairstyle is based on Yuji Tonogaya, from Magical Girl Apocalypse.