Both shows deal with two teenage boys finding love and developing a relationship, moving from friends to lovers while dealing with issues such as identity and one's past. There are some differences of course - in "His" there are two major female characters who advance the story, and "Given"'s backstory is a more tragic, but overall - those who like Given and Japanese BLs in general should give "His" a try. Also, watch the sequel movie (titled "His").