Extreme Shiritori is an online game based on the "Genkai Shiritori (限界しりとり)" game originated by QuizKnock.

[What is Shiritori?]
"Shiritori" is a simple Japanese word game similar to the English game "word chain". The word "Shiritori" translates to "taking the rear".
Players say a word beginning with the last letter of the previous word.
For instance,
quiz, zebra, ark, knock, knowledge, enter, ...

In Extreme Shiritori, players must enter a word with a specific number of letters for each turn. The game also has a time limit.

[About QuizKnock]
QuizKnock is a knowledge-based intelligence group of students from the top universities in Japan.
The goal of the group is to provide people of all ages with enjoyable learning experiences through quizzes on a variety of media sources including websites, YouTube, books and so on.