Kimi wa Seifuku wo NuidaraKimi wa Seifuku o Nuidara; 君が制服を脱いだら; When You Take Off Your Uniform

Kozu Ippei, a high school boy with a scary-looking face but mature (motherly) personality, runs into Yayoi, a cute but devious college girl. Misunderstandings lead to more misunderstandings, as they fall in love. (Source: Ichijin Plus)