Shijou Saikyou no Deshi Kenichi 2: Tatsujin-hen

From Shogakukan: Kenichi Shirahama, a hopelessly ordinary high school student, was guided by Miu—an incredibly strong young girl—and now spends his days training at Ryouzanpaku, a place where masters of various martial arts and combat styles gather! Just as Kenichi has grown and become stronger by overcoming incredible trials, a new enemy makes an appearance... Could it be a ninja?! And to top it all off, his old companions and his sworn enemy, YOMI, have also returned...