The first Hilichurl you will run into on Day 4 of the Mimi Tomo event in Genshin Impact is the Restless Hilichurl. He has a Mutual Exchange quest for you, which means he is looking for a specific item, and if you can give it to him, he will give you some information that you need.
The good news for players is that they have the Handy Handbook of Hilichurlian that they can use to look up different phrases that the Hilichurls will use. The Hilichurl will use the phrase “Gusha Celi Boya”, and we will need to figure out what it wants.
Gusha translates to fruit of vegetable, Celi translates to heat or light, and Boya translates to red. So, it seems the Hilichurl is looking for a red fruit or vegetable. We gave him a tomato and he was perfectly happy. If you want to do the same, you can find tomatoes in the general stores in Liyue or Mondstadt. You can also try any other red fruit or vegetable and see if it works. Give him the relevant item, and he will as happy as a clam and will proceed to give you the next piece of information that you need, which is actually the location of the next Day 4 Hilichurl.
Players can open the Handy Handbook of Hilichurlian at any time by going to the Mimi Tomo section in the events menu and hitting the prompted button for the Handbook near the bottom of the event description. There are quite a few Hilichurlian phrases in there, but it’s still pretty easy to figure out what these little guys are talking about, thankfully.