Kobayashi Takeo is a total geek, a klutz, and the cause of all of Nick's suffering. He is in the same grade level as Nick, and they became friends when Nick entered high school in Tokyo. Takeo, as stated, is a total geek, and an avid otaku. Takeo comes from FMA OVA canon, where, within canon, Fullmetal Alchemist as a television series exists. So, when Takeo met Nick, an actual Elric, he latched on like a rabid little fanboy. Fortunately for him, Nick didn't mind.
Takeo is smart in a lot of ways, and really really dumb in others. He knows he looks like Mustang and uses it to get away with things - occasionally - but most of the time manages to goof it up.
Takeo and Nick managed to somehow send themselves through the Gate to Amestris, where they puttered around for a while causing a lot of gray hairs and trauma. They were still in Amestris when Takeo opened a door and they found themselves in the Nexus house. As in a lot of things, Nick blames Takeo for this.
He wears glasses but doesn't like them, however he is blind as the proverbial bat without them. He has a pair of contacts somewhere, but he loses them all the damn time.