I Suddenly Became a Girl, So Would You Like to Grope My Boobs?

Synopsis

Sakio's world shatters when he awakens to find himself inexplicably transformed into a girl. As confusion turns to panic, he seeks answers from his best friend, but their attempts to understand his new form led to an unexpected and arousing encounter. Now a girl, Sakio must desperately conceal his secret and fight to retain any semblance of his old life, as his stepbrother's inappropriate and unwelcoming interest grows. (Source: Coolmic)