Stable, happy couples don't tend to make for great reading, but they do provide excellent happy endings. Robico's My Little Monster has never fully promised us either of these things as it followed the rocky, awkward romance between emotionally wounded Haru and deliberately cold Shizuku, but this final volume of the main story (there is a thirteenth book comprised of short stories) still manages to bring things to a very satisfying end without ever compromising the characters or their issues.

Largely Robico is able to accomplish this because she has been slowly allowing the four main players – Haru, Shizuku, Asako, and Sasayan – to develop as the series has gone on. Very little of their development has been obvious, with an excellent use of quiet growth and subtle changes that have allowed us to see their evolution without even really being conscious of it. While this began to truly become obvious in the preceding three books, with Sasayan finally saying something many readers may have suspected from the early volumes and Shizuku truly thinking about why she is the way she is, this final book brings everything to both a head and a conclusion.

Two of the most effective ways this is accomplished are both in the third (of four) chapter. This chapter, entitled “Third Years,” is almost entirely dialog free, showing us the passing of the characters' final year of high school in a series of vignettes that not only give us a good sense of what is actually happening, but also of how Shizuku has changed since the start of the series. If you hadn't really noticed or thought about it before, even in light of her words to Haru in the second chapter of this volume, this montage really drives it home. From facial expressions to body language to clothing and hair, this is an excellent depiction of someone growing up in a natural way. There aren't any shocking revelations, major life events (beyond graduation itself), or any of the other tricks both YA literature and shoujo manga typically employ to show character growth; just the slow, steady reality of how things change based on who we are and how we interact with the world. That Haru and Shizuku have been able to do so through each other is what makes this a romance rather than a simple slice-of-life. (The difference is important simply because a love story is not part of everyone's daily life experience.) In fact, it's almost more important that they have gotten to know each other as friends and taken so many volumes to come to a point where they are comfortable with their relationship than that they have a romantic relationship at all.

And by this point it is a romantic relationship. Few things drive this home better than the letter Haru sends at the end of chapter three. Letters have a long history in literature of saying what the characters cannot say out loud, with one of the best examples being in Jane Austen's Persuasion, the famous “You pierce my soul” note from Captain Wentworth to Anne Eliot. Though Haru's letter isn't quite on that level, it is wonderful and provides the reassurance we and Shizuku need that things will come to a happy ending. More importantly it gives a voice to the key component of their romance – that Haru somehow saw himself as less than human, but Shizuku gave him the chance to come to understand himself as a person.

That's the greatest strength of this series finale. When we met them, both Haru and Shizuku had walled themselves away. Through their interactions they were both able to come to accept and understand themselves, as well as what made them close off in the first place. Ultimately they become able to function as individuals because of their time as a couple. They don't need each other in the co-dependent way romanticized by a lot of other romances (shoujo or otherwise), but are stronger people because they have known each other. That's not something you see within the genre very often, and Robico manages to use it while still providing a traditional happy ending. It's heartwarming and it also marks My Little Monster out as a series that functions outside of its genre parameters to give us that most unusual thing: a healthy relationship in shoujo romance.