Mister Ishikari is a supporting character in the anime Yumeria. He serves as the teacher of Tomokazu Mikuri’s class at school. In terms of background, he is an adult male with short brown hair and brown eyes, typically seen wearing a suit and tie.

His personality is marked by a clear duality. On the surface, he is kind and courteous to all of his students except for Tomokazu. Toward Tomokazu, he is openly cruel, holding a personal grudge that seems to stem from jealousy. It is noted that he used to be kind to Tomokazu, but the relationship soured for reasons related to his own insecurities. He is also characterized by a heavy lolita fetish, which he admits openly, making him come across as even more perverted than Tomokazu despite being a figure of authority. He is described as strong-willed and handsome, but his actions are often petty and vindictive.

His primary motivation appears to be jealousy: he resents Tomokazu for the attention he receives from the attractive girls around him. This jealousy fuels his antagonistic behavior toward his student. In the story, Mister Ishikari fulfills a supporting role, functioning mainly as a comedic antagonist rather than a serious threat. He has no involvement in the dream world or the central conflict against the Feydooms; his presence is confined to the real-world school setting, where he provides lighthearted conflict and comic relief through his over-the-top reactions and inappropriate admissions.

Key relationships center on Tomokazu, toward whom he is consistently hostile and petty. He does not have significant connections with other characters beyond being their teacher. The character undergoes no notable development or arc over the course of the series; his personality and behavior remain static. He possesses no special abilities or powers, relying only on his position as a teacher to exert minor authority.