Once you reach Chapter 4 in the main story, the "Tea for Two" quest will become available. Upon completing the quest, the player will receive a tea set. From then on, you will be able to invite characters from your own house, or any character attaining C support with Byleth, to have tea at the cost of one activity point.

Although it just looks like fanservice, there are decent rewards from having tea with others that make it worth the cost of one activity point.

If the unit accepts your invitation (which seems to be complete RNG, luckily this can be save scummed), you'll be immediately taken to the teatime minigame.

There are 5 potential stages during teatime, each having a correct action and many incorrect ones. For each correct action that you take, you earn one Evaluation Point. The amount of Evaluation Points that you accumulate throughout the teatime determines your rewards at the end.

The first stage is to choose which tea to serve. Each unit has a list of teas that they enjoy, choosing one of these teas will earn you one Evaluation Point. Then, you will hold 3 rounds of conversation. During each round of converation, there will be 3 options for topics to talk about. There may be 1 or more topics that the character is interested in, choosing one of these interested topics will earn you one Evaluation Point per round. After the 3 rounds of conversation, if you have earned 3 or 4 Evaluation Points prior, you will move to the final comment. Like the rounds of conversation, there will be 3 options to choose from, with one or more correct answers. Choosing the correct option will earn your last Evaluation Point, for a best-case total of 5. If you fail to get any Evaluation Points after the first two conversations, the teatime will end.

You will only have 15 seconds to choose a response. However, you can home screen to pause the timer, effectively giving you all the time you need to look up the answer.

You will gain support for your teatime, and potentially points of Charm. Both are dependant on how many Evaluation Points (EP) you accumulated throughout the process. Each unit can gain a maximum of 2 Charm from teatime per month. A single RN per teatime character is rolled to determine whether or not they gain Charm (assuming they haven't hit the cap).

Guessing which topics to choose based on a character's personality can be pretty tricky, given that half of the topics are generic phrases such as "Children at the Monastery". Visit a character's personal page (search here) to see a list of their preferred topics.

To help with this, we've built an assistant tool that allows you to get perfect teatimes every time and farm that charm. Check it out by tapping the floating button on the bottom right, or by clicking this link.