If you're looking for manga similar to Ikken Cool dakedo Futsuu Kawaii Shinoda-san, you might like these titles.
A "delinquent" who freezes up and says violent things when around women meets a small girl in the library when he's out studying. To his surprise, she tutors him, even though an elementary student shouldn't be able to. As it turns out, she's a high school student and his classmate; she's eager to befriend him. Also surprising to him is the fact that he isn't afraid of her. Could it be because he sees her as a kid? Or does he?
Takahashi-kun is really into Shimizu-san who is known to say exactly what’s on her mind to everyone. This is what happens when she's totally straightforward with him as well.
Onizuka is an Oni and her childhood friend Sawarida is a human who likes to touch weird stuff. She might be in love with him, but he is too dense for love or is it the other way around?