I did read the first post. You specified Japan only but you did not clearly specify why.why arent people reading the original post? -,-
i know all games that were released in the west so no point in calling out those games.
Anyway, the only game and I can really recommend is Nanashi no Game (The Nameless Game). It's a horror game that's halfway decent. There's also Clannad, if you're into visual novels.