Kain is free ... and he's out playing with the flow of time! Seems that Tenchi is involved in a sort of time paradox: in the present, Tenchi doesn't exist! With Washu's help, the group is going back to that distant land of 1970 to undo the damage that has been done, and prevent Tenchi's parents from breaking apart ... or worse!
I'd say I like this movie better than Tenchi in Love 2. It doesn't have as much of a dark side. Though Tenchi is disappearing he isn't constantly being attacked. I don't really have much to say about the movie but I did enjoy it and would recommend it to other anime-aholics.