@PsychicDoom, it's a watered-down version of Fumika's route tbh. Then again, the main game feels kinda incomplete without an Akebi route (the twin sister).
@cybeast93, there was no sister route planned when they were making the main game. Similiarily, they didn't make a sister route in Tincle★Twinkle Festival. But they made a very big 10 anniversary FanDisk and added sister routes to both Otome Switch and Tincle★Twinkle Festival afterstory since a lot of fans wished there would be a sister route, if my memory didn't cheat on me.
Still the main game was incomplete beacuse they said a small game woudl be implanted soon but eventually it's gone. If you still remeber, it's a naval war game (I'm not sure if I remember correctly) indicated in the scenario.