Reading this manga is a bit weird, I thought this was legitimately a yuri/sport manga because it dealt with the subject of the MC having issues of having huge breast but meh, it's just another trash ecchi manga that tried to sell you on the idea of having on a real story. the main focus of this story is the character's breast and how she is shy around having big breast. Does anything interesting happen? nope. is there character progression? nope. Is there a central focus on bowling? nope. it's just porn and honestly, the mangaka is better off making some doujin otherwise there is no reason to read this manga if you're not stroking it really hard.