Don't people want to meet their relatives just 'cause they're relatives? I don't need a special reason.

[Shinji might not be related to him by blood, but they are family, and it'd be good to talk to him at least once. Maybe they'll get along, maybe they won't, but one conversation wouldn't kill either of them.]

Plus, he's probably super worried about Sakura and Rin right now. Somebody should tell him they're okay.