The Anime Lad
Leon is reborn inside an otome game he remembers playing, but not as a prince or romantic lead. He is a minor noble in a society where his prospects are narrow and the academy runs on status. Leon intends to use his game knowledge quietly. Quietly is doing considerable work in that sentence.
Super Eyepatch Fox
An office worker wakes inside a punishing otome game as Leon, a noble with background-character status. He remembers routes, items, and systems the important characters do not. At an academy where romance, rank, and giant machines overlap, that knowledge offers a route toward independence and a reliable source of new trouble.
Gigguku
This world has fancy school uniforms, brutal marriage politics, and fully armed mecha because the original game apparently feared restraint. Leon remembers the mechanics and has exactly enough resentment to exploit them. Watching a supposed extra use walkthrough knowledge against polished romantic leads gives the usual reincarnation fantasy a gloriously abrasive little engine.
Father's Basement
Its social satire often uses a hammer where a raised eyebrow would work, and Leon's contempt can become its own repetitive gag. The hook remains sturdy. He is trapped as a minor character in an otome game he knows inside out, where aristocratic romance shares space with airships and mecha. System knowledge becomes class mobility with consequences.