I'm sorry to say this irresponsibly: this post was updated after the first comment was received.
BBC to
Sherlock faced the irredeemable John and was helpless about living alone in the future, but was saved by a little girl who suddenly broke in.
CP Xiang Fuhua Weimailei
Thunderbolt: The heroine is 14 years old
The heroine will do something for Sherlock that Sherlock can't do, in order to win over Fuhua. The heroine is also relatively pitiful. While she envies Fuhua, she also feels sad for her own situation. She comes to 221B through Mai to seek protection. In the process, they became very good friends, which can be regarded as an iron triangle.
I feel like the tags are not very reliable[.] Oh, by the way, if there were no comments, I probably wouldn't keep updating.