It was short, a tad odd at points but genuinely a rather well made use of the premise. The story actually, somehow, made both Lili and Riona's love of Elemy not feel perverted in context.
Lili's love is a mix of confused feelings of romantic, parental, familial and teacher love that even she seems seems almost confused by due to his age and behavior. But her root desire was family and a sense of belonging. Briese's death made her colder and lonely but Elemy being her former master's reincarnation means his personality likely retriggered her internal warmth. In part because she wishes to pay it back for Briese's care for her.
Riona's strikes me as "damaged" girl with secrets finds an unusual wunderkind and outright abandons what was likely a fake romance to investigate him to a full blown genuine one. However she has very little to go by in terms of love and/or courting besides her training and is likely even more bewildered by Elema's personality being a far more mature person than he should be at his age. Literally he's an adult in the body of a child whom tries to strike down all her overarching demands for marriage thus making her even more invested.
Elema for his part actually plays his role very well; he doesn't lust over either girl while also showing an underlying attraction, likely due to his hormones. Likely one of the best made Reincarnation stories in regards to that sticky subject; you don't get any hinting that he'll hook up with either romantically for the long foreseeable future.