18+ Yankee Kanojo to Kozukuri Gakuen Life

The protagonist was a weak guy, so when beautiful yankee Ayame rescued him he was smitten. When he found out one day that she was may be forced into an arranged marriage, he mustered the courage to tell her how he felt. Impressed by his moment of manliness she said, "If you really like me you'll steal me!" It was the touching start of a vulnerable, awkward, schizophrenically emotional love life.

(Source: dlsite)