Letter to Totoro

I really loved Letter to Momo, don't get me wrong, but did anyone notice similarities to My Neighbor Totoro? I'm not trying to say its a rip-off or anything, but dang there was a lot similar - all in good ways though - but in the end its definitely a completely different film.
The premise has a girl who just recently moved encounter three mystical creatures, along with a handful of minor spirits - Totoro has two sisters come across soot sprites and three Totoros. Both of the big reveals (at least for Satsuki and Momo) of the spirits happen during the rain. Both have sick mothers, whose worsening conditions by the third act of the film cause the children to make rash decisions to travel by themselves, in which a spiritual 'bus' has to help them get to their destination (both of which are hospitals of a sort). By the end family relationships are restored after varying degrees of tension.
Granted there is a lot that is different in both films. Something that was refreshing about the imps in this movie was that they weren't inherently good - they talk about eating people, they look out for themselves often first, and they steal. In the end they do care about Momo, though. King Totoro, Chibi Totoro and Chu Totoro are more laid back and fun loving, I don't think they have a nasty bone in their furry (and sometimes transparent) bodies. They'd rather plant trees than steal oranges.