Sake is a Japanese traditional alcoholic beverage made from fermented rice. And what is SET???
First, I thought that is something like KIKIZAKE SET (利き酒セット) which means tasting of different kinds of Sake. But it wasn't. Searching google image "SAKE SET" seems to represent the kit of Tokkuri (徳利) and Ochoko (お猪口), the carafe and cups. Hmmm, google search is so useful! WIKIPEDIA describes not only Tokkuri and Ochoko. It describes all type of carafe and cup, glass for drinking Sake.
Anyway, I'm not intending to talk about the definition of SAKE SET, so here I would describe about Shuki (酒器) which translate literary "vessels for Sake"
There are various type of SAKE SET and each of it has unique feature to enjoy drinking Sake. As you may know Sake has a various temperature to drink. Lips feeling and also enjoying full aroma is important to choose a cup. Here, a general simple description to select cup and server.
As Rosanjin Kitaoji (Japanese artist) said "Serving dishes are the meal's apparel" Japanese dishes are selected to present the season, for instance coolness glass for summer and warmth pottery for winter, and also select wares for guests hospitality.
Before selecting SAKE SET, I'll recommend you to know the basic knowledge of selecting Sake cups.
Amount of filling Sake will change the taste. At drinking cold Sake, finish before the temperature changes, because as you may know the taste is relating with temperature, so smaller size maybe recommend.
2. A diameter
Surface area of the Sake depends on the cup's diameter. Increasing surface area increase volatilization of aroma.
Opened wide cup makes aroma strong. Rounded shape, which top is narrow make the taste rich.
4. Material feelings
Glass and metal feels cold, earthenware feels warm and lacquer feelings is warmer than earthenware. Porcelain stands between Glass and earthenware.
This is just a generally said. The most important thing is to find out your favorite way to enjoy Sake!
Or first to Rakuten Global refer
But maybe not needed because it's easy to do.