I thought it was Marisa...

So Letty rooms up in Yukari's winter sleep room for the other 3 seasons.

^
That makes a surprising amount of sense

I was translating this for a while, but one interesting thought just appeared to me.
Why in the world Yukari can provide Letty with infinite amount of conditioners and fans, yet she has to snatch Cirno to cool herself?

Cuz she doesn't want to foot the electricity bill.

CyrusVorazan said:
I was translating this for a while, but one interesting thought just appeared to me.
Why in the world Yukari can provide Letty with infinite amount of conditioners and fans, yet she has to snatch Cirno to cool herself?

It's a doujin, it's supposed to be funny.

The door "appeared". It's safe to say that Yukari provided a boundary to wherever Letty was. I don't think that room is on their property, let alone in Gensokyo.

IchiMashiPotatos said:
The door "appeared". It's safe to say that Yukari provided a boundary to wherever Letty was. I don't think that room is on their property, let alone in Gensokyo.

This.

Also, PMiSS makes a point that Yukari is a "Youkai's Youkai". She never does something in a simple, straightforward manner if there are crooked/oblique/bewitching ways to do the same.

Something like: Gapping arctic air in = human thinking. Kidnapping an ice fairy = youkai thinking.