|Japanese name:||真瀬 由子|
|School:||Himematsu High School|
|Grade:||Third-year high school|
|Debut:||Saki (manga), round 68|
|Voiced by:||Haruka Yoshimura|
Yuuko Mase is a third year at Himematsu High.
Yuuko has blonde hair tied into many bun's and blue eyes. She wears the standard Himematsu uniform.
Playing Style / Abilities
While at first glance it appears as though Yuuko is a normal player with no outstanding abilities, unlike Himematsu's vanguard and lieutenant, Yuuko is seen to be a formidable player, having a positive score in both the quarterfinal and semi-final matches. Even when Mako goes on the offensive in the semi-finals, Yuuko valiantly says that she is not yet finished and tsumo's.
National Tournament Arc
She first appears along with the rest of Himematsu in the first round of the tournament, watching Kiyosumi's match on the waiting room television. Yuuko informs Hiroe Atago that Kiyosumi is doing well and explains how the game went. When Himematsu advances to the second round she is among the others watching Suzu Ueshige's match.
After Suzu apologizes for her defeat in her match, Yuuko tells Kyouko Suehara not to worry and to leave the others to her. Her match is only scarcely shown but during the match, even though she is puzzled by Mako Someya's weird play she did manage to gain points before it ended with Mako taking the lead.
She is then shown before the Vice-Captain match wondering why Nodoka Haramura is so popular. After Kyouko managed to place second, Yuuko and the rest are shown welcoming her back. When Yoshiko Kainou is introduced to the team, she and Suzu gets very exicted and ask her about the legends going around about her.
Final Eight Arc
Yuuko is shown along with the rest of Himematsu entering the tournament hall. She is later present to send of Suzu before her match. While discussing the match and Suzu exploding, she says that she can't wait for it to happen.
With Yuuko being the first dealer, she immediately calls a chii and says that she will focus on extending her dealership. After Hao Huiyu discards, Yuuko calls pon. She then notices that Chikako Himori takes a while to discard a tile and wonders if she is in tenpai before Chikako wins with a tsumo. When Hao wins a hand, Yuuko notices that it was a pure shifted chow, which is a chinese mahjong yaku. After another win by Hao, she rons Mako for a win. When Mako declares riichi, Yuuko says that she rarely does that but she tends to win if she does. Immediately after Mako's win, Yuuko wins with a tsumo and says that she hasn't lost yet. When the match is over it is shown that Yuuko has finished with possitive points and protected Himematsu's second place standing.
Before Hiroe's match, Yuuko scoffed at Kinue for trying to explain her sisters joke, saying that her sister having to explain is scary. During the match, Yuuko notes that Hisa Takei is probably protecting Usuzan's player for going bust before the match ends. Yuuko appears in Kyouko's flashback in the captains match. Two years ago Hiroe and Kyouko were talking and Yuuko mostly makes one line comments, but wants to be friends with Kyouko as well. After Kyouko's slump, Yuuko noticed her improvement.
Back in the waiting room, Kyouko apologizes for the loss but Yuuko and Hiroe tell her not to worry about it. When Ikuno reminds them that there is a match tomorrow, Yuuko says that it'll be tough playing early in the morning but it'll be a short match.