Manga can be
appreciated on different levels.
NOTE: To do this, you must be able to read kana, but no knowledge of Japanese beyond this is required. In fact, it is probably better if you have none.
One way to do it is this. Get a manga that is about absolutely nothing at all. The less it's about, the better. Make sure it has plenty of pretty pictures. And it must have furigana.
Lie down. Open your manga to the first page (the page at the "back", Japanese read "back" to "front", like Semites). It probably has a pretty picture. Look at it. "Aaa, kawaii".
Go to the next page. Read the text aloud. Try to get the voices right. It is good to sound silly. Keep reading and looking at the pictures.
This is a perfect activity for when your brain needs rest.