Len is the oldest son of the family trio. He worked alongside his Dad, Kouji, and his brother, Masaki. They initially went missing after visiting a mall infested by cats.
He has a yellow spiky hair with brown eyes, a white shirt and dark blue jeans. He can also seen wearing a yellow shirt with paw shapes underneath and using a extra shirt tied on his waist.
Len wields dual yellow crocodile shaped water gun as his signature "weapon".

Due of being completely overwhelmed by cats, they are forced to take shelter in storage room. But unfortunately, their dad got infected trying to buy them time to escape.

He and Masaki was found hiding in a storage room by the main trio who are guided by a green furred Rex Devon cat, surviving on snacks within it.
Afterwards, they join the trio to gather supplies and then try to escape.

(Source: Nyaight of Living Cats EP6)