I'm on the same page. Relationships with Takeshi?
Though I'll be the first one to break the ice and say that maybe Takeshi and Kazuo are somehow affiliated? Perhaps Kazuo is "that senpai" he would go to help to, or whatever. And they'd enjoy eating sweets together because last year Tak was in the baseball club...
And since headband-senpai is athletic, I thought there would be some other club and so some interaction?
Let me know what you think!