The best replacement for clannad is kanon.

The best alternatives to clannad are rated as following:
★★★★★  kanon
★★★★  air
★★★  clannad after story
★★  angel beats
★  steins gate
★  toradora
★  little busters

Your alternative for clannad is not listed? Suggest!
Speaking about clannad, one probably shouldn't forget about enya.

Other search terms related to clannad and their ratings are:
★★★★★ enya
★★ mary black
You have in mind a companion for clannad and it is not yet here? Propose!



Google Trends

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clannad
kanon
air