(from ebookjapan):

In Meireki 2 (1656), the reign of Shogun Tokugawa Iemitsu came to an end and it was the time of the sickly and young Ietsuna. Yasutsugu Miura was the lord of 30,000 koku of Shimono-Mibu.

The story begins at the Kuromatsu mansion under the castle where the Miura family fosters their eldest son. Sohei Kura, a skilled member of the Onimichi Shu, sneaks into the Kuromatsu mansion and searches for clues to the Golden Castle. Then, Saihegawa Hoshinosuke, a human with the same powers as the Onimichi Shu, appears and crosses blades with Sohei.

The first volume of "Yoseiden" depicts the charm of the original story full of imagination with unique sensitivity and brushwork.

Leiji Matsumoto's manga adaptation of Ryo Hanmura's SF novel Yoseiden.