Items

You can find items that are hidden on the map by walking near their location (you have to discover them). Some monsters also contain items when you encounter them. There are multiple item types (e.g. catch items, TMs, bait, ...)

To catch a monster you need to have at least one catch item (you have only a few when starting a new game). Catch items are precious here! Trainers in the anime don't throw balls at everything, and you shouldn't do it as well. Catch the ones you really like first, and establish a deep relationship with them.

Aside for the first batch initially available, additional catch items can be found in various ways:
 * 1) By following a radar that will guide you with visual and hearing hints (blue arrows, light sparkles and beeping sounds) - (Otherwise you can just keep the game open as you travel in car/train/bike and hope to find them accidentally, but since it's a low-effort method, the faster you travel and the lower will be the accuracy).
 * 2) By defeating npc trainers (explained below).
 * 3) By buying them in the in-game shop.

You can find evolution-inducing items on wild monsters, you'll see a specific icon when they have them. Sometimes they drop the item as soon as they get defeated, otherwise you can catch the whole monster and therefore get its item without fail.