“Sudoku & Logic Puzzles for Home Vol.4”
“Sudoku & Logic Puzzles for Home Vol.4” contains about 100 puzzles, mainly Sudoku and Logic Puzzle.

“Have a Ball with Pencil Puzzles–Kakuro for Expert 2”
“Have a Ball with Pencil Puzzles–Kakuro for Expert 2” contains over 90 Kakuro puzzles for experts.

“Have a Ball with Pencil Puzzles–Slitherlink for Expert 2”
“Have a Ball with Pencil Puzzles–Slitherlink for Expert 2” contains over 90 Slitherlink puzzles for experts.

“Puzzle Communication Nikoli Vol.179”
Nikoli is the most advanced pencil puzzle magazine in Japan. The first issue was published in August, 1980.

“Footprints of Maki Kaji”
A stroll with Maki Kaji: A collection of writings, illustrations, and catchphrases, written by Maki Kaji.

“Cho-Gekikara (Really, really hard) Sudoku” contains 91 sudoku puzzles.

“Nankan (Hard) Sudoku” contains 105 sudoku puzzles.

Announcement of discontinuation of the SmartNikoli app. On July 31, 2022, all services on the Nikoli app for smartphones “SmartNikoli” will be terminated. From August 1, downloading of SmartNikoli will not be possible, and continuing to play the puzzles on this app will also not be possible. At the cessation of services all information of registered members will be deleted from our records. The last new puzzles on SmartNikoli will be uploaded June 30 (JST). Uploaded puzzles will be available for play till the end of July, 2022.

We deeply regret any inconvenience the discontinuation will give rise to, and apologize to everybody affected. At the same time we wish to express our appreciation and thank you for the time you have been registered for and enjoying the puzzles on SmartNikoli.

A heartfelt thank you to everybody goes only a short way towards expressing our appreciation and thanks for your support. At present Nikoli is working on a new smartphone-dedicated service which will be announced on our website. You have something to look forward to!

“The Best Selection of Supersized Puzzles Vol.1” contains 40 supersized puzzles.
All the problems included here are selected from “Puzzle Communication Nikoli”.

“Flash Puzzles by NIKOLI” contains over 40 puzzles that need a spark of inspiration.
Knowledge of Japanese is necessary to solve puzzles in this book.