説明書

A flower. 花見 is going to look at cherry blossom; 花火 is fireworks — fire flowers.

Half of 瑠璃, the deep blue stone. On its own it is used mostly for its sound and its colour.

A younger brother, and anyone junior to you. In 弟子 it means a disciple.

Japan wrote London as 倫敦 long before katakana took over. That is where this character gets the ron sound.