I, am Playing the Role of the Older Brother in Hearthrob Love Revolution

From HaruPARTY:

I’m a very ordinary girl who had no interest in Otome games, and was suddenly sucked into the world of a cliche Otome game, Heartthrob Love Revolution. That’s all well and good, I’m not exactly thrilled, but it’s fine. However, why am I the heroine’s older brother? I’m a girl! My character is named Makoto, and as him I hang out with the Heroine to help her get together with the princely character and make it to the end credits. All righty, I just need to support the Heroine while she does her best. If I do, I think I’ll be able to go back to my original world…but wait, why am I so popular? Hey, prince guy, don’t you blush at me!