tsuka, Kasanariau Ashita e (いつか、重なりあう未来へ, lit. "Someday, when Tomorrow Laps") is a Japanese dating sim Playstation game developed by Sony Music Entertainment. The game was released in 2 versions focusing on different protagonists between male (Shiro) and female (Sayuri).
The year 2049, where the Earth is attacked by an unknown alien race labelled as ESSAR (Extra Sol-System Alien Race). To combat the threat, the protagonists as students of the "UNIT (UFN Named Institute of Tactics)" Military Academy befriend other students while eventually learning new piloting tactics for the "Vectride (ヴェクトライド)" mechs.
Like any other dating-sim, play through the right choices to strengthen the bond of the player's choice. The bond between the protagonist and his/her interactions with the fellow partner(s) of selection determines the resonance level of the Vectride's parameters during battle.