Takako Shimizu is Hideki and Shinbo's teacher at the Seki cram school. Like Yumi, Shimizu has had a negative experience with persocoms: her husband bought a persocom and eventually she became unimportant to him compared to the persocom. He spent more and more time with his persocom until he forgot about his wife completely, locking her out of the house one night because he was so enamored with it. Because of this, Shimizu was no longer able to trust human men.