|“||If you can make your opponent think that there are traps, you can disable a large part of their ability to make judgement.||”|
Shinji is a man with long, slicked-back hair, styled in a short ponytail under his head. He has facial hair in the form sideburns on the sides of his face and a goatee on his chin.
He is very easygoing and calm. Possibly due to him being older than most agents, he occasionally refers to himself as "this old man".
- His given name is written with 慎 ("act with care, be cautious") and 次 (next, secondary, following), while "Fuyushima" (冬島?) literally means "winter island".
- He likes games, sukiyaki and lego blocks.
- He was ranked 78th in the first Popularity Poll, before he was even introduced, and 49th in the second one.