I've always loved Mizutani Fuuka's works ever since i read Lonely Sheep , Lonely Wolf. The stories just gives you this warm feeling inside when it comes to the love between same gender or age difference. All of Mizutani's works kinda gives the message that gender and age doesn't matter when it comes to love and you should definitely take the chance that is given. Game Over's main story is quite enjoyable and although the artwork is not extravagant, it matches perfectly with the setting of the stories. The sub stories are pretty interesting too XD

Please do give the author's other works a try too:
-Lonely Sheep, Lonely Wolf
-Like a Cinderalla