Steins;Gate - episode 10 - 07 Jun, 2011

Okabe realises the D-Mail Faris sent prevented moe culture from being introduced into Akihabara. As Okabe wonders why the relationships between his friends have not been affected, he comes to realize that Ruka's gender had in fact changed to female as a result of his/her D-Mail. Afterwards, Okabe talks with Suzuha, who reveals she came to Tokyo to try and find her father, mentioning she will leave if she is unable to find him the next day. Okabe then establishes her as a lab member and invites her to the lab. As the other lab members prepare a farewell party for Suzuha and an offer to let her send a D-Mail if she fails, Okabe receives a threatening text message telling him that someone is watching him, with a picture of a gelatin treat attached. Later, while shopping with Mayuri, he realizes that his ability to retain memories from previous timelines first occurred when he was a child. That night, Suzuha does not show up and simply sends a farewell text to Okabe. Okabe runs around the city in search of her, failing to notice that the satellite that had crashed in the Akihabara radio building has disappeared. He decides to send a D-Mail to himself telling him to follow Suzuha, shifting to a world line where she ended up attending the party and staying in Tokyo. (Source: Wikipedia)