This is a doujin game by Chainsou.

Nayuta lives with his mother in the not-too-distant Nipponbashi in Osaka while working on creating apps for smartphones. The Nipponbashi Street Festival (Sutofes) has had growing attendance over the years, but it has particularly garnered a lot of attention this year with the expansion of the underground shopping centre, being featured in the world’s premier internet company Eagle-sha’s real map web service Roadview and also being supported by the mayor. Nayuta and his friend Hajime went to the underground idol concert and met the idol Rikka, and he was charmed by her song. He also happened to met a new system engineer from Eagle-sha, Chisato, with whom he had often chatted online.

While set in Den-Den Town, the focus of the game appears to be rather on family relations. Nayuta dropped out of school in order to help out his divorced mother. Chisato gave up everything she had to become an engineer in order to gain her parents’ love. Rikka was raised by a foster father and doesn’t know her true parents.

[From Hau~ Omochikaeri!]