Note: This game is also known as - Subarashiki Kono Sekai: It's a Wonderful World

Completion bonus - Successfully complete the game, and save when prompted. You can start a new session with your cleared saved game file with most of your previously obtained items and skills. There will be an option to select any chapter to replay with bonus objectives at the cellphone menu. You can now select "A New Day" chapter and go to Shiba-Q Headquarters. At the third floor, you can purchase the Ultimate difficulty as a quest item. The "Another Day" chapter will appear at the chapter selection menu.

Hard mode - Successfully complete the game on the Normal difficulty to unlock the Hard difficulty.

Alternate ending sequence - Collect all of the secret reports, including the one in Another Day, to view a bonus scene after defeating the final Boss in the main story.

Save game file icons - Successfully complete the indicated task to unlock the corresponding character icon at the saved game screen:

Beat: Successfully complete the third week.
Joshua: Successfully complete the second week.
Mr. Hanekoma: Collect all secret reports.
Mr. Mew: Get 100% Pin Mastery.
Rhyme: Collect all items.
Rhyme (noise form): Successfully complete the noise list.
Shiki: Successfully complete the first week.

View total play-time - At the save data menu, hold L + R.

Easy PP points - When you save and turn off the Nintendo DS, you will gain PP points for the pins you have on. You can use this to your advantage by changing the system date. Save your game, turn off the Nintendo DS, turn it back on, go to the date setting, then set it forward by seven days. The Nintendo DS will turn itself off after you are done. Turn it back on, and load your game. You should gain PP points for seven days. Repeat this as many times as desired. Once done, save the game, and change the date back to the correct value.