Kano Castle

Some refer to them as the Shinshioka Nobles, they are one of the most powerful clans in the game, owning 8-9 rice villages. Kano Castle is Seiki's destination when he sets out on his delivery mission from Fuyu. He finally gets there after many detours, but is coldly received. Seiki and his friends decide they do not like this clan.

Kano Castle is responsible for the dissolution of the Jigokuryu Clan.

Yoshinaga (clan leader - samurai)
He is the owner of the Ire of Izanagi (+201 attack), allegedly the most powerful sword in the game, which grants the user an eight-fold cut ability.

After Seiki makes his delivery, Yoshinaga realizes his plan to send a message to Renshiro failed. To test Seiki, the man asks to purchase Renshiro's armguard, which Seiki refuses. Yoshinaga forces Seiki to consume a mysterious drink. The drink turns out not to be poison, but the snow elixir drink which gives 2500 XP. Seeing how perplexed Seiki and his friends are, Yoshinaga and his clan mate Fumiya have a good laugh.

At the end of book two, Yoshinaga is at level 28.

At the start of book three, he is assumed to be level 29.

Fumiya (ninja)
Second in command, Fumiya is a level 29 ninja described as tall, slim, with long straight black hair hanging down past his waist. Seiki first encountered the ninja at Kano Castle where Fumiya had hidden in Camouflage and threatened his friend as part of a prank to coerce Seiki to drink the mysterious liquid. They meet again in Seiki's instance at the end of book three, where Fumiya was waiting for whomever to finish the quest in order to kill and loot them. Seiki and his friends however, managed to kill him and escape.