I’m very happy with this hat.
In order to please Prince Onion, I bought all the onions in America and built an onion palace.
I hope you’re happy with your new puppy.
You enter into the energy. When you're entering (positive) energy into something, you are going to be pleased with it. Just imagine yourself adding some physical, happy energy into something you're pleased with. Smile and feel pleased as well!
The 気 portion is pretty straight forward. The 入る portion looks like it's supposed to be はいる but it's not. Do you remember 入れる／いれる? This one is kind of a mix of both of them. It's just いる. Just imagine you're so pleased with something that you just put everything together and end up with a combination of both of them (they both are so pleasing!). So it's not はいる and it's not いれる it's いる.