Yamada Momoka is your average 16-year-old girl. Her family consists of herself, her dad who works at a TV station, and her mom. Apparently, she also has a strict prune of a grandma, but who doesn't? Except that the grandma, Yamada Tamaki, had an accident at the TV station where she got electrocuted and now looks like a 16-year-old Yamato Nadeshiko.

It isn't easy for Momoka when her grandma arbitrarily decides to attend Momoka's high school as a student as well. Tamaki isn't just pretty, she's also very cultured, well-mannered, and still maintains her old-fashioned streak from her 65 years of wisdom. It's bad enough when Momoka starts being referred to as "Old Yamada" and her grandma (Tamaki) referred to as "New Yamada", but it's even worse when Momoka's crush on a dashing young man starts to take an interest in Tamaki as well.

Fight-o, Momoka! Protect your beloved grandma, Momoka! And don't let her walk off with your boytoy, Momoka!

Notes:
- Includes 1 extra chapter
- Includes the one-shot "Keshin Panic (化身パニック)"
- Includes the one-shot "Ichigo Gyuunyuu na Yatsu (いちご牛乳なヤツ)"
- Includes the one-shot "Uchi no Hide (うちのヒデ)"
- Includes the one-shot "Uraha Umi (うらはうみ)"
- Includes the one-shot "Kaeru to Hime no Dilemma (カエルと姫のジレンマ)"
- Includes the one-shot "Daisuki! (大好き!)"