Hosuke first appears as a talking owl suffering from amnesia, discovered perched in the X-Zone. This light teal owl possesses a distinctively long tail, unusual for his kind. He becomes a steadfast companion to the main characters, offering wisdom and guidance despite his fragmented memory. Hosuke demonstrates an understanding of the X-Zone's ancient language and experiences sudden flashes of forgotten knowledge, though their origin eludes him initially. He displays a particular attachment to Makoto, frequently staying near her.

His past unfolds: Hosuke was originally the High Priest and King of the X-Zone, a close friend of Takeshi Yamato. Two decades ago, while they investigated a decline in Imperial X's energy, Takeshi accidentally triggered Hosuke's transformation into an owl. This curse also erased Hosuke's memories of his human life. The incident occurred as Takeshi was transported to Earth through an interdimensional tunnel. Time flowed faster in the X-Zone, causing Hosuke to age into an old man during Takeshi's brief absence before the curse finalized his owl form.

As events progress, Hosuke's memories gradually resurface, especially during crises threatening the X-Zone's stability. He is ultimately unmasked as Yuki's grandfather, a connection he confirms after the revelation. Following the defeat of the ancient evil controlling Takeshi, Hosuke reclaims his throne as the X-Zone's king. He plays a key role in stabilizing the energy flow between dimensions, enabling safe passage between Earth and the X-Zone. Once stability is secured, he chooses to remain in the X-Zone but later journeys to Earth alongside Sho Yamato, indicating his restored ability to traverse the balanced worlds.

Hosuke's personality blends wisdom with moments of levity, often providing a steadying presence. His journey from a bewildered, memory-lost owl to a restored monarch highlights his crucial role in safeguarding the X-Zone's legacy and secrets.