Yuki Fumino's I Hear the Sunspot stand-alone graphic novel is one of the sweetest love stories to be translated into English, BL or otherwise. That sets the bar very high for its sequel volume, I Hear the Sunspot: Theory of Happiness, and while it doesn't quite achieve the understated beauty of Kohei and Taichi's initial romance, it is still a charming exploration of what it means to be in a relationship with someone, be that friendship or something less platonic. It's also a thoughtful look at how people with disabilities are treated by those without, and even though Fumino's words speak directly about hearing loss, her words will resonate for anyone with anything that marks them as somehow different from the accepted norm.

Part of what makes this feel slightly less wonderful than its predecessor is the fact that, after apparently seeing Kohei and Taichi get together at the end of I Hear the Sunspot, Theory of Happiness opens with them decidedly not dating. Both young men are feeling awkward about the kiss, and Taichi is particularly conflicted about the fact that he might feel something beyond friendship for Kohei. For Kohei's part, he's fairly certain that he's managed to offend or alienate Taichi with the kiss, and the two have maintained semi-silence for a while. It's awkward and annoying, but also feels true to both how friends who might be moving beyond that simple designation may act, and also very, very human – “ignore it and it will go away” is a method espoused by most people at some point or another, even though it's been consistently proven not to work. But there's a further complication for the two that feels somehow even more obnoxious: the entrance of Maya, a new student, on the scene. Maya is also hearing impaired, and in a very similar way to Kohei. The two met when her uncle asked Kohei to talk to her about going to college, and she quickly formed an attachment to him. All of Kohei's talk about Taichi inspired her to be jealous of him before ever meeting him, so when she finally does come face-to-face with him, Maya's predisposed to detest him on sight. (The fact that Taichi is clearly trying to help her makes this more annoying than it needs to be.) She thrusts herself between Taichi and Kohei, helping to make their already strained relationship more awkward.

It is, perhaps, a measure of just how uncertain the two young men are about the status of their relationship that she's able to do this. Taichi in particular feels that he's not worth Kohei's affections – he's been told time and time again that he's rash, loud, and not especially good at anything. This forms the impetus for his major decision towards the middle of the volume, as well as a solid thematic element of the book as a whole. As Maya's life was changed by meeting Kohei, who gave her the affirmation she needed to go to college, Taichi's life is changed when someone besides Kohei sees value in his outlook on life. Having Kohei tell him that he's a good person is one thing, because his uncertain emotions make things more complex than they need to be. Having a completely outside individual do the same gives Taichi the push he needs to make things right, not just in his relationship with Kohei, but in his relationship with himself. Kohei is finally able to see his own value, and that's ultimately what leads the volume to its successful conclusion.

While this may feel like excessive angst at times (and it does), it also grounds the love story in the idea that loving yourself is integral to being able to fully love someone else. That's the journey Kohei took in the first book, and this one is Taichi's version of that same voyage. (Presumably if we do get the third volume that Fumino mentions in her afterward it will be about their growth together.) One of the pivotal moments for Taichi is when he's trying to explain why he believes that the hearing impaired and the deaf should be given the same opportunities for assistance; he says that it's lonely to always feel different, and that with a little care, no one would have to. Even though he's talking about Maya and Kohei, you get the sense that he's also talking about himself, that his “perky dippy guy” persona has become a burden to him. Just as Kohei found acceptance through Taichi, Taichi found that same acceptance through Kohei, and that's what they've both been trying to put into words all along.

I Hear the Sunspot: Theory of Happiness is almost twice the length of the first book, and that does help to alleviate the angst factor. While it would have been nice to simply see Kohei and Taichi being happy together, this approach does make more sense for the characters and it allows Fumino to explore some deeper themes about what it's like to live with a disability, be that physical or otherwise. With its delicate linework and soft designs, this is a genuinely nice story to read. Even if BL isn't your genre, if you like romance at all, this is a duology (hopefully future trilogy) that is worth your time.