Kenji Sato is a 26 year old, famously known baseball player throughout the States and Japan. Who also happens to be the "superhero" Ultraman. Like his father, Professor Sato, once was.

Kenji has a AI assistant named "Mina" that can control his house and pretty much do anything.

Kenji's mother, Emiko Sato, is M.I.A at the moment.

While being a popular baseball player AND Ultraman, Kenji has to struggle with raising a very large Gigantron baby in secret, hiding her from the KDF (Kaiju Defense Force).