Diamond no Ace Wiki
Natsukawa Yui
Seidou High School
Bats: Throws:
Kanji 夏川 唯
Gender Female
Age 16 (debut)

17 [1]

Date of birth 13 August
Height 157 cm
Weight 44 kg
Education 2nd Year High School (debut)

3rd Year High School [2][3]

First Appearance
Manga Act I - Chapter 7
Anime S1 - Episode 4
Voice Actor Karin Takahashi

Natsukawa Yui (夏川 唯) is a student of Seidou High School and one of the managers of the Seidou Baseball club.


Yui has short light brown hair that has bangs covering the left side of her face.

Relationship with other characters[]

Umemoto Sachiko[]

Sachiko and Yui know each other well and joined the baseball club together. They are in the same year of high school. Yui knows that she can rely on Sachiko and vice versa. They trust each other blindly regarding their work as team manager.

Fujiwara Takako[]

Takako is Yui's reliable upperclassman. It was a tearful farewell when Takako and the other third years retired.

Yoshikawa Haruno[]

Haruno is a fellow manager and one year younger then Yui and Sachiko, and thus their kōhai.[4] But Haruno is very clumsy. As a result of her clumsiness, she often makes more work for her seniors, which leads to them getting angry sometimes. But after some initial difficulties they get to know each other really well and start to work together as reliable teammates.


  • Natsukawa means "summer" (夏) (natsu) and "river, stream" (川) (kawa).
  • Yui means "solely, only, merely, simply, common" (唯).


  • Yui and Takako call Sachiko “Sacchin”.



  1. Acr I - Chapter 201
  2. Act I - Chapter 412
  3. Act II - Chapter 1
  4. In Japan, kōhai (後輩) is a junior.