Name: Yuya Sumii
Designation: Kamen Rider Gaim
Gear: Sengoku Driver, Lockseeds
Yuya Sumii is the former leader of Team Gaim who went missing in Helheim Forest after having obtained a Sengoku Driver from Sid. After accessing the Yggdrasill Corporations database, Mitsuzane learns that Yuya ate a Helheim Fruit and became the White Tiger Inves that Kouta kills when he first became an Armored Rider. Though Mitsuzane tries to protect him from the truth, Kouta is horrified once he learns that he has unknowingly killed his friend.