In 2008, the Japanese government began hunting people who identify as otaku in an effort to protect the country's culture. In just one week, the enforcement agency known as the SSC captured almost every otaku by force and confiscated their memorabilia. One passionate man calling himself Otaku Hero refuses to allow this agency to do as they please: he raises a resistance army made up of other displaced geeks who band together to help defend their culture. Three years later, the fires of rebellion wane as all hope seems lost for otakus. Spurred on by his ally—the magical girl Anarchy—Otaku Hero commands the resistance in an effort to reunite Anarchy with the other two other magical girls: Blue and Pink. By combining the power of this trio, the resistance may be able to defeat the SSC and save otaku culture for everyone.

Miki Takekasa is an introverted high schooler who does not socialize with her classmates. However, she wants to know what fun really is, waiting for someone who could help her understand its true meaning. One day after school, she crosses paths with her classmate Aya Takayashiki, who takes her on a little adventure. Miki discovers wonders she had never seen before, opening a way to change her withdrawn life. On their way home, Miki and Aya see their class representative Midori Oono entering Saikoro Club, a store specializing in board games. After trying out a German board game, Miki soon understands the kind of fun she had been looking for: playing various games after school along with the friends and acquaintances she makes from her newfound pleasure.

Jun Shirasaki and the Jinguuji sisters are childhood friends and neighbors. When Jun's first girlfriend, the older sister Rumi, breaks up with him, she says something that complicates the three people's relationship, their first loves, and their romance—? (Source: MAL News)

Second season of Grand Blue.