Steins;Gate

Rintaro Okabe is a self-proclaimed "mad scientist" who believes that an international organization is conspiring to reshape the world according to its own interests. He and his friend Itaru Hashida inadvertently create a gadget able to send messages to the past. The discovery and experimentation of this instrument become the catalyst of fundamental alterations to the present. Oblivious of the consequences of their actions, Rintaro and his friends end up creating modifications of grievous proportions. He must then try to find a way to return as close as possible to the original timeline in order to save his precious lab members.

Synopsis from Anime News Network