A bookish girl with glasses becomes a mystery-solving magical girl, except the magic isn't the point, solving the puzzle is. The transformation is just permission to be clever out loud. This is for kids who read mystery novels instead of watching TV, suddenly seeing themselves reflected back as the hero who uses her brain to save the day.
Hinami is a bespectacled girl who loves reading, and she spends her days with two good friends. Whenever a mystery turns up, she changes into Nazotoki-hime, a sharp-witted persona whose name roughly means Princess Mystery Time, and sets about working out the answer. This short 2012 OVA mixes magical girl transformation with puzzle solving across six episodes, which were released on bonus DVDs packaged with issues of the shoujo magazine Ciao.