The Friends system is a feature added in version 2.3.0. It allows players to pit their ships against other players without relying on the randomized exercise system. Friends can also assist the player in certain events.
After clicking "好友" button on the main interface, you will see this:
Now you can visit your friends' room and challenge their loved girls :) First 3 challenges (with different friends) can gain exp.
Notice you can only have maximum 30 friends in your list!
This screenshot shows all of the applications sent to you. After checking their profiles, you can accept or just decline. Up to 100 applications will be saved.
To send application, you only need to know their UID.
You can only add users in the same server! If you friend's account didn't create character in your server, the application will not be received.