This is a sweet and refreshing frozen pie. You just take it out of the freezer and slice as-is, so it's like an ice cream pie. I had the taste of key lime pie in mind when I made this.
I love key lime pie, so I thought that if I added some lemon, it'd be even more tart!
Americans use cups (1 cup = 250 ml). If you heat the lemons and limes (especially the limes) in a microwave for about 10 seconds, they'll be easier to squeeze.
Enjoy Japanese food around the world.