Yeah it should be AI ni Iku
会う - to meet あう (au)
会いに行く to go to meet あいにいく (ai ni iku)
会いに行こう let's go to meet あいにいこう (ai ni ikou).
And then it's not chuugen
it's nakama
仲間 (なかま)
chuugen 中元 - 中元 【ちゅうげん】 (n) (1) 15th day of the 7th lunar month; (last day of) Bon lantern festival; (2) (See お中元) Bon gifts; (P)
taichi X
tachi (as in a group, emphasizing the pluralness)
Sunuupii to Nakamatachi ni ai ni ikou!
Let's go meet Snoopy and Friends!
Who thought they were smart enough to transliterate the title?
And yes, he's still very big here in Japan, though I get the impression out of Japan, the U.S., and Europe, he's the least popular in the last these days.