I use Kaomoji a lot. They’re cute and expressive emoji frequently used by Japanese people. On iOS you get a list of Kaomoji when switching to the Japanese keyboard layout and clicking the ^_^ button. I never knew something like that was built into Windows too (I always used to copy them from this website)
When switching to Japanese input on Windows PCs, simply type かおもじ (“kaomoji“) and the Kanji prediction list will show a wide range of Kaomoji for you to select!
Similar to this a lot of Japanese words can be replaced by a symbol when writing them. Typing じてんしゃ (bycicle) will result in 🚲 and typing みぎ (right) will result in → symbols. Other ones are かお (face) for ☺ and かっこ (brackets) to get the typical「」 quotation brackets.
There are many more to discover and they can definitely make typing much faster without having to move your mouse and select a certain icon from a big list. Experiment and have fun!