What's the first VN with heterochromia?

[Okarin]

I'm playing through Shuffle, and it got me thinking if it actually started the heterochromia trend. Certainly, in old anime this wasn't to be found.

Mayumi is great.

[Decay]

Well, the earliest VN with the "heterochromia heroine" tag on VNDB is Dolls Front, which seems kinda obscure. The next was two years later, Angelic Serenade, where the main heroine has it. It was a much more popular VN, made by the studio who later made Symphonic Rain.

There are no VNs from the '80s and '90s with it. Anidb lists a variety of shows from the '80s and '90s with it, but I can't really tell how many of those are have them on prominent characters, or use them for the moe factor. At a glance, very few, if any, do. GTO is an early example of that. But yeah, plenty of other anime with heterochromia prior to Shuffle.