Matsubue was the main character of Discommunication and Discommunication gakuenhe (a small side story at the end). He was also one of the main characters in Discommunication seireihen (a manga series which involved dream users eventually lead to another manga called Yume Tsukai.).
Matsubue also had a cameo appearance in Nazo no kanojo X OVA and played the mysterious kidnapper along with Togawa and at the end stole a pattern design from Urabe's yokata.
Matsubue has a strange,eccentric personality and seems to always be calm and nonchalant, he also seems to be a hermit as he lives by himself away from the city in a house full of religious objects and D'art. He enjoys doing things with Togawa this includes involving her in rituals to help her out in certain aspects (in one ritual he summons Dakini which gave Togawa a great sleep after she gives him a pillow for his birthday).
Matsubue has mysterious powers he seems to be able to shake the ceiling of his house just by looking at it and stop a stray baseball from hitting him by looking at it. He can also go in and out of illusions and control them as well as summon gods and deities when ever he sees fit.
Mutsubue is the boyfriend of Togawa but at the start of the manga he appears to have no interest in her apart from his bizarre requests which range from cutting her hair and tickling her to tasting her tears and involving her in rituals. Later on in the manga they grow closer and he even risks his life to protect her.