|Release Date||November 26, 2007|
|Previous||The Couple's Feelings|
|Next||Two People and One Person|
Mask (仮面, Kamen) is the ninth chapter of School Days manga.
While on a date, Kotonoha and Makoto stop by the local toy store. Kotonoha is quickly attracted to the cuteness of a stuffed bear and Makoto expresses surprise, since he didn't know she liked stuffed animals. As Kotonoha goes to grab a stuffed dog, her hand bumps into someone else, revealing Sekai to be standing there. Makoto expresses surprise and Sekai teasingly asks them if they are on a date. Both of them reply that they are, and she mentions that she was on an errand to get materials for the upcoming school culture festival.
Kotonoha invites Sekai to join them, and Makoto agrees to it. They come to a dress shop and Sekai decides to pick out a dress for Kotonoha to try out, then asks for Makoto to wait for them in the changing room. Sekai teases him by telling him not to peek, and this annoys him. She then kisses him before closing the changing room cloth to separate them.
At the fast food restaurant, Kotonoha thanks Sekai for finding some clothes for her, and Makoto is also in a good mood. Sekai tells Kotonoha that she has been changing since she first met Makoto, and she discusses how happy she is to be with him. She explains that because most boys look at her with "dirty eyes", and girls tend to be envious and dislike her, due to her appearance, so she has cheered up a great deal. Before she starts to talk about how happy she is with Makoto, Sekai stops her and mentions that Makoto is a good guy and is glad she introduced them to one-another.
As the trio make their way home, Sekai tells Kotonoha that she needs to borrow Makoto for her errand. He apologizes to Kotonha for the inconvenience and they part ways at the train station, leaving Sekai with Makoto. As this is going on, a young girl sees the two of them together, but gets called by her friends.
Sekai invites Makoto back to her place and brings him to her bedroom. They sit together on the bed and Makoto attempts to speak with Sekai, but she kisses him and they make out instead.