He is something of a child genius, and deeply interested in the Denjuu World, which he had never visited before. After he and Shigeki accidentally arrive there via the D-Shot that Shigeki picked up, Matsukiyo stays with Musa in Tronco Village and gives Shigeki advice during the course of the story.Kyou and Midori, giving them a map and D-Shot so that they can travel the Denjuu World and find their fathers. He offers rewards through the D-Shot's Wanted application, in exchange for information on specific Denjuu. He also rewards the player with a certificate if the Denjuu Index is completed.
Matsukiyo is never encountered as a T-Fanger, however there is a set of battle sprites for him in the ROM image data.
In the manga
In the Telefang 1 manga, Matsukiyo takes a much more active role than in the games, exploring the Denjuu World with Shigeki. He befriends a Waratah in Tronco Village, which becomes his partner Denjuu. There are also a series of 4-koma featuring Matsukiyo in volume 3 of the collected set.
Matsukiyo also appears in the Telefang 2 manga.