(From the publisher):
Long, long ago... Bontenmaru commanded the Oou, but now he has joined the Shiseiten! He joined the dark side because they were far stronger than any troupes he had ever led. Now he is extending Kyo an offer to join his side. Regardless of Kyo's decision, he will need to return to his master and the one that forged his sword... the legendary Toushou Muramasa!
Original title: サムライ ディーパー キョウ
Genre: Fiction→ Fantasy→ Historical