|Voiced by|| Asuka Tanii (Japanese)|
Ema Kogure (Japanese) (Episode 223-236)
Kristi Bingham (Funimation)
Judy Cheung (Hong Kong)
Leibi Wen (Taiwan)
|Age||13-14 (Estimation, around Natsumi's age.)|
|Species / Type||Pekoponian|
Yayoi acts like your typical high-school girl. Natsumi and Satsuki are her childhood friends, and out of the two Yayoi seems the most calm.
- Satsuki Shiwasu-Childhood Best Friend. The two are always shown together, proving how deep their bond is.
- Natsumi Hinata- Childhood Best Friend. Natsumi barely spends time with Yayoi, due to being busy at home. The two see each other as friends nonetheless, Natsumi even giving Yayoi her strawberry when she gets turned into Natsuo.
- Giroro- Current Crush
- Keroro, Momoka and Saburo- Friends
Shimotsuki is the traditional Japanese name for the month of November.
Yayoi is the traditional Japanese name for the month of March.
- Her friend's name, Satsuki Shiwasu, is also formed from two traditional month names.
- Yayoi's special talent is spinning dishes. 
- Yayoi may be based off of Natsumi's Friends.