Fuku

This small, rabbit-like creature originated from an egg aboard Seina Yamada's vessel, the Kamidake II, and was personally named by Seina. As the younger sibling to Ryo-Ohki, the daughter of Washu, she shares a unique biological connection with Ryo-Ohki, serving as the initial and fluctuating power source for the ship, Kamidake II, directly tied to Fuku's emotional state.