I drew a couple of my own, since I love that series.
These are characters, that little that they know, were actually long lost childhood sweethearts, when they supposedly met each other, for the first time.
The male among them, is Hanz; a prinny, that was one of the few, that were wrongfully convicted, and was therefore, transformed into one, by accident. Thing is, he ended up liberating a netherworld, known as "Asylum Land", from an overlord, that was taking things WAY too far; even going against democracy. (He was soon killed off by this guy, of whom isn't an ordinary prinny.) Not long after that, the liberated innocents, celebrated his demise, and voted on Hanz being the new overlord; Hans accepted this, only because, this place NEEDED a new leader. (Since of it, "Asylum Land" became a much friendlier, silly place; despite being imperfect.)
The female among them, is Katrina; a felynn, that was in the past, blackmailed into being a cat burglar, for a living; this was to ensure her parents would live. Fortunately, the ones responsible for blackmailing her are dead, and with her parents safe and unharmed, she could finally move onto a better life, and retire from being a cat burglar. Unfotunately, she was caught by a corrupt overlord's thugs. Fortunately, she was saved by Hans, and, the the two of them, had soon became bussom buddies. (But, she's only PART nekomata; her dad's a prinny.)
How did they fall in love? As it turns out, Hanz had a childhood sweetheart, of whom was called "Casey". As it turns out, Casey had survived, and as it turns out, she wasn't a human; she was a nekomata girl, that disguised herself as a human, to avoid having cultists hunt her down, and to learn more about the midworld, where humans lived. Katrina had not only forgotten Hanz, (due to a side-effect of a spell that wore off) but back then, she also never revealed her true identity to Hanz because, she didn't want him in trouble and, she wanted Hanz to live a nice, happy life.
Hanz did not care; regardless of whether his sweetheart was a human or not, he still loved her, and found it interesting, that she was actually a felynn / prinny mix! Even saying, "Let's face it; a world with only humans, would be dull, dood!"
The two of them had soon become a couple.
= Hanz, Katrina, and the artwork, are (c) by me
= The "Disgaea" franchise, is (c) by Nippon Ichi Software