I was introduced to the series when I was about 5-6 years old. Lunatea's Veil had only recently been released. Back then though, my sister and I more often rented video games from one of the local stores rather than bought them. We didn't have anything like Super Nintendo 64, but we did have a PS2, and I was usually the one picking the games to play. Usually I rented Spyro, but my guess is that it had been rented out when I came across Klonoa 2: Lunatea's Veil.
Long story short, my six year-old self was drawn to the cover of the game. I thought it looked like a fun game and we rented it out. My sister and I fell in love with it and we rented it several times from then on.
After the section of the store where we could rent the game was closed down, we were unable to play it for a few years. I don't think I got into it again until I was maybe 12 years-old. I pleaded for my mom to look for a copy and luckily, she found one eventually. I've had it in my collection ever since.