Sadamitsu is a virtual copy of Kamina. He spends the entire anime yelling about how he never runs from a fight and engaging in the most ridiculous grandstanding, even trying to fight giant aliens with his bare hands. It's great!
"Who do you think I am, you shit gorilla?" Can you tell which of the two animes this is from? Me neither!
As far as shounen action series go, Bleach has become something of a measuring stick and Sadamitsu the Destroyer measures up quite well. If you replace Hollows with aliens, you pretty much have the concept of Sadamitsu the Destroyer. Both are about somewhat delinquent high school students who are thrust into fighting monsters with powers they don't completely understand. In addition Sadamitsu the Destroyer has very likable characters to the which have you rooting for them almost instantly despite the anime's short episode count. (Remember how much you cheered on Ichigo and Rukia in the first 10 episodes of bleach!)
Holy Crap! He did NOT just link an shounen action series and a school romance slice of life series together!!
You bet I did. Though it's pretty much a one way compatibility. If you liked Sadamitsu the Destroyer, than you probably like action, but if your a little deeper and also enjoyed the unrequited love story built into the plot than Green Green may provide you with the same little twang on your heartstrings. I'm not sure how many hard core slice of lifers who usually look down on any shounen anime will take to all the fights in Sadamitsu the Destroyer.