LOVE AT FOURTEEN (14-sai no Koi), by Fuka Mizutani. First published in 2010 and first published in North America in 2014.
PLOT:
Kanata Tanaka and Kazuki Yoshikawa are both seen by their
classmates as cool and mature. None of
them would suspect that the two are old friends who revert to giddier, more
childish versions of themselves when alone.
Lately, though, the two can’t help but notice how attractive the other
has gotten. As the two start to fall in
love, they find themselves straining even harder to keep up their cool facades
while finding opportunities to enjoy some quiet, tender moments together.