Manga by author Hinachi Nao

From Senpai Scans:To change from 'like' to 'love', what strategies must Ozawa use on Kazuki?Kazuki Heiji is the troublemaker. He gets into fights and is very cold to everyone. Ozawa Kii witnesses a fight between a classmate and Kazuki but he unexpectedly says he wants to become friends? And what's this about 'like' and 'love'...?!

From ShoujoHearts:The heroine Hitsuji is nicknamed "Kigurumi-chan" by her surroundings. While she is friendly with everyone thanks to her easygoing personality, she is distressed about not being treated as a girl. She's always had an unrequited love for her classmate Touya, who always quarrels with her.One day, the number one popular boy in the school and the student council president Fujiwara-kun suddenly gives her the new nickname "Mojako"...