The discourse about whether this series is a BL or not is asinine. Of course it is. Male-male love does not have to be consummated to be a BL; it merely has to be perceived. At its core, this series is that. Most assuredly, it is a love story of unrequited love. In addition, this series is certainly a GL. More overt but never fully realized.
The story is a deeply reflective, pensive at times, coming-of-age narration of four inquisitive high schoolers. Each is hiding an inner secret not atypical of individuals of their age. But for all, it seems crushing and perhaps overwhelming. That is the burden of youth they must carry - until their next quest.