Side Story
Anecdote, Episode
noun
Insert some extra talking into a story, and you have a side story!
挿話 is a relatively formal word that refers to a short anecdote or little episode inserted into a story that isn't essential to the main narrative but adds some additional context, background, or flavor.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
これには、面白い挿話があるんですよ。
There's an interesting anecdote about this.
ワニカニが出来るまでの、ちょっとした挿話があれば教えてください。
If you have any anecdotes about the creation of WaniKani, please share.
『吾輩は猫である』の中で特に面白い挿話は、猫が初めて餅を口にする場面です。
One particularly amusing episode in "I Am a Cat" is the part where the cat eats mochi for the first time.
この小説の魅力は、本筋の合間に織り込まれた心温まる挿話にある。
The charm of this novel lies in the heartwarming vignettes woven in between the main storyline.