This manga has slowly grown on me, because it can take such odd circuitous routes to its central sentimental theme about learning to accept the differences of oneself and others, in order to achieve happiness.
...This latest chapter has managed to turn my brain into scrambled eggs mixed with macaroni and cheese, and I'm not even sure whether or not that's a good or bad combination. Horse.
The younger sister (Mii, Mitsumi and Top eye) are all pretty awesome.
Seriously remind of 3 x 3 eyes through
There's also the protagonist of an Osamu Tezuka series, who displayed a different, more aggressive personality when his third eye was open. (The series is Mittsume ga Tooru, if you're curious.)