|Japanese name:||白築 耕介|
|Family:|| Nana Shiratsuki (sister)
Shino Shiratsuki (niece)
|Debut:||Shinohayu the Dawn of Age ch 1|
Kousuke is uncle and caretaker to Shino Shiratsuki and brother to Nana Shiratsuki. He used to be in a band and was called Richardson. He hates tomatoes. Shino reveals that he is a writer for a music magazine.
Kousuke has short blonde hair and green eyes.
He seems to love food (as long as it does not involve tomatoes) and deeply cares for his niece Shino, though he seems to be struggling with being a parental figure to her after her mother's disappearance.
Kousuke is first introduced playing with his neice when she was a baby. Years later, he comes to visit his sister and brings her a present before playing three player mahjong with Nana and Shino. After being beaten by Shino, he notes that she has improved her mahjong skill as well as her cooking. When Nana went missing, Kousuke became Shino's caretaker.
A year later, he is shown eating Shino's food and asks her to go with him to the shrine and pray. The next morning he notices Shino's mahjong tile set and sells them when she is at school. When he gets home, he notices that Shino is in a panic about her tiles and he informs her that he sold them because he thinks a reminder of her mother is hurting her ability to move on. Kousuke is next shown getting up early to take Shino to the shrine. He then stops to get her something to drink only to notice that she has vanished.
Children's Tournament Arc
Flustered, Kousuke rushes into Sudou's Pawn Shop and asks if he has seen his neice, thinking that she came there to buy her mahjong set back. When Syunto Sudou answers no, he then gives him the drink he intended for Shino before departing. He then travels to her elementary but has no luck in finding her. Kousuke then goes to the house and searches everywhere before uncovering her paper mahjong set and a flyer for the children's tournament. When he arrives he sees Shino on the big screen and realizes that she is having fun. Kousuke then finds himself a seat to watch her play in the finals.
When Shino isn't doing so well, he says that just getting fourth overall is impressive. He then proceeds to get annoyed at the people making comments behind him, but then brags about his neice when she starts to do well. After the game, Kousuke apologizes to Shino for telling her to quit mahjong and not being there for her. He also says that he's glad that she had fun and that he is going to support her from now on. Later that night he gives back her mahjong set.
Before Shino could get to the door, Kousuke opens it to welcome her and is greeted by her and her friends. He then wonders where she got the yukata.
Before the start of the the 12th annual Matsue Children's Mahjong Tournament, he seeks out his niece and offers her durian juice. He then says that he'll be watching from the audience and departs. He is then shown cheering throughout the match for Shino. After she wins the tournament, he picks her up in joy.
After the tournament, Kousuke heads to Tokyo to meet with his Editor-in-Chief. They talk about him moving to Tokyo but he tells the editor that he hasn't the money to do so. Kousuke then tells him that Shino is searching so hard for her mom and that he feels he should do something. The editor then tells him that he's done his own digging and hands Kousuke a report showing that Nana worked in Ginza prior and was a very high class hostess. However, every six months, a mahjong match takes place there.
When he gets back, he greets Shino before they get to their house and then she cooks for him. Shino then tells her uncle that she is trying to get into Askumi Girls' because she doesn't want to burden him and if that can't happen she'll look for live-in employment. Later she informs her uncle of the class visit and says she didn't tell him about it because she felt like if he went then she would be resigning to the fact her mom is gone. However he goes anyhow, making Shino happy.
Girls of Yumachi Arc
After noticing Shino doesn't have a bicycle, he calls Syunto to order one. When he says he doesn't have one, he buys her a new one and they thank each other. He then tells Syunto that he feels kind of lonely.
Children's National Tournament Arc
As they prepare to leave for the tournament, Kousuke asks if anyone will see her off. Shino tells him they already gave her a send off but Kana asked about her flight time. When they arrive in Tokyo, Kana and Kyouka are there to greet them. Kana then says that they are there to support Shino and they are staying at Kyouka's grandparents house and wants Shino to stay there as well.Kousuke wonders if that is okay but Kyouka quickly makes sure that it is. Shino then departs with her friends and Kousuke goes to a work related meeting. At the meeting, the editor is depressed that Shino isn't coming with Kousuke and wants to have a drink before doing work. The next morning Kousuke awakens in the office thanks to his phone. The editor tells him that he was following up with the detectives and what they had to say. He tells Kousuke that Niemann came to visit two years ago and there was a rumor going around that she lost in an informal match and that it might have been Nana. Kouskuke quickly dismisses this. When asked if he has told Shino about their conversations, Kousuke said that he hasn't because Shino has been feeling great about mahjong and telling her would result in something bad.
Immediately after Shino's match, she meets her uncle and asks if her match was on television. He tells her that it wasn't and they head to lunch.
End of Summer Arc
At the house, Kousuke informs Shino that all of her official match expenses will be paid for by Nana's former boss. He said the boss was doing it so that he could recover an excellent employee.
After Shino is finished with her phone call, he notes that it was unusual for her to talk on the phone in front of him, but was glad because he got to see a cute side of her. At night Kousuke and Shino played with the fireworks he got from his editor.
While coming home from work, Shino show him her middle school uniform and wants to model it for him. With the uniform on, Kousuke says that she reminds him of his sister. He then takes a photo of her.
City Tournament Arc
As Shino arrives home, Kousuke decides to cook for her again. While she is stirring the rice, he mentions that if anyone is bullying her to come to him immediately. At the table he is frustrated that he had to give up on cooking somethings. They then talk about Nana. Later Shino asks if he can make it to her match and he says he can. He then greets her before the match.
When Syunto comes back with drinks, Kousuke tells him of how the vanguard match ended. When Kanna Ishitobi passes by he says that she is Shino's friend but it's hard to say anything to her at the moment. After Shino's match, she meets up with him crying. He asks what's wrong but Syunto tells him it was because of the match. Kousuke then tells her that when she was upset before she use to run and head-butt him and it would be okay for her to do it now. She then backs up a considerable distance and does so.