VisualNovel review
VisualNovel is built around AI stories that can include several characters in one interaction. Its public terms also distinguish one-time credit purchases from subscription payments.
The unused-credit condition after a renewal
The terms give 30 days from payment to request a refund for an unused purchase. They describe an unwanted renewal separately. A refund of the most recent renewal requires that none of its credits have been redeemed, and the credits are revoked if it is refunded.
Writing a scene with more than one character
Flirti AI centres its creator on a companion’s personality and appearance, with choices for private or public sharing. VisualNovel’s terms describe AI narration and multiple characters in the same story. If you already know you want a scene with a cast, that format matters before you decide how many credits to buy.

Anabel’s take
I'd pick VisualNovel when I want two or three characters to affect the same story. I'd use the smallest credit purchase that fits the scene before deciding whether I want a balance arriving on a schedule.