“Elementouch (Maeno’s Invention)” was introduced in “Textbook of Elements” supervised by Takeo Sakaki.

Chapter 1: Fundamentals of Elements “New Style Periodic Tables” (p. 19)

• “Textbook of Elements”
  supervised by Takeo Sakaki
  Natsumesha
  https://www.natsume.co.jp/books/18738