It should end like this: Yahwi and Cain meet somewhere, fell in love with each other and are happy together, Jooin is miserable because he didn't know what he wants and lost all. He then buys a hamster and end. ┑( ̄Д  ̄)┍
It was a manga about 2 highscool boys. One can only eat (life) energy. After eating from the other guy He coudn't eat anything else and collapsed. The school doctor was also someone eating energy.
That everyone's forgetting the sister