Pleasant surprises abound in Ivan Reitman’s romcom about an aspiring TV writer (Ashton Kutcher) and a med student (Natalie Portman) who try to carry on a sexual relationship without getting their emotions involved. Portman, clearly enjoying a break from Serious Movies, shows real comic chops, while Kutcher’s lack of electricity comes across here as laid-back affability. He’s the sheep dog of leading men, generously allowing his castmates, including Kevin Kline and the adorable Greta Gerwig, to run their more extroverted performances through his shaggy coat. Though its story about fuck buddies, one of whom is an emotionally unavailable woman, invites comparisons to Love and Other Drugs, this movie isn’t so concerned with pulling dramatic strings. Reaching for lower-hanging comic fruit, Reitman comes up with a solid handful of laughs.