Miwa Rengaya

Professor Shiouji's mother, who is much more intelligent than her son. She showed up out of nowhere and moved into Shiouji's lab, then frustrated Shiouji's attempts to find out more about Kabapu and his father and started working with Kabapu. The "affection" she hoists upon her son is the reason he's a pedophile.

Only appears in the manga.

She is revealed to be Sanshiki Ropponmatsu, which explains her personality change.