Happy Sudoku

Happy Sudoku is a free-to-play Sudoku game.
Sudoku is a game where you fill in empty squares with numbers. The basic rule is to place the numbers 1 through 9 exactly once in each row, column, and 3x3 block without repetition.
Most questions are relatively simple, so even beginners can enjoy them. Advanced players might find them a bit too easy, but please aim to clear all the questions.
Play Happy Sudoku and get happy!

[How to Play]
Clear the game by correctly filling in all the numbers 1 through 9, using each number exactly once in every row, column, and 3x3 block!

[Memo]
Tapping the “Memo” button toggles the memo feature ON and OFF. When ON, tap a number at the bottom of the screen to enter memo.

[Hint]
Tap the “Hint” button to automatically fill in the correct number for the selected square. Starting from the 4th hint, you'll need to watch an ad.

[Check]
Tap the “Check” button to check your answer. Incorrect squares will be highlighted in yellow. Starting from the 4th hint, you'll need to watch an ad.

[Question Types & Quantity]
Questions can be selected from three difficulty levels: “Easy,” “Normal,” and “Hard.” New questions will be added continuously. If you've cleared all questions, please wait a while until new ones are added.

[Who is this for?]
*People who love Sudoku
*People who haven't tried Sudoku yet but want to
*People looking to kill time
*People wanting a brain workout
Anyone can enjoy playing!

[Supported Languages]
Languages are supported in Japanese and English. Language switching is not supported within the application. The language is switched according to the language setting of the device. (If the language setting of the device is Japanese, the application will be displayed in Japanese. If the language setting of the device is not Japanese, the application will be displayed in English.)