Both muchachos (male lead) have something that the chiquitas (female leads) crave for.
Both muchachos are have no idea that the chiquitas only wanted what they have or what they can do.
Both have the same, school, romance, comedy and some ecchi genre.
One is a rich man's son, while the other is a screen writer.
One anime has a lolicon element in it, while the other has a drama element.
In one anime the muchacho (male lead) has a love interest, while the other anime the muchacho (male lead) is simply in search for his supposed sister.
The other anime is only 10 episode long (OVA included), while the other anime may be 12 or 13 episode long.