Total Recommendations: 3
Both of them have magic, the main characters both wants to be a great magician and they makes a contract with a human who becomes there partner. Also they have to defeat an evel force.
If you liked the comedy in Seto No Hanayome then you'll love the comedy in Golden Boy, you will laugh so much that your stomach will hurt.
Both of them are ecchi and about love with sibling(s), but Aki-Sora is more ecchi than Kiss x Sis, more hentai like (you can almost see everything) and between real siblings and therefore a forbidden love. If you want a awesome really ecchi sex scene (not hentai, just looks like one) then you should see this anime/OVA.