I suppose the government intervened since diabetes was growing at an alarming rate and asked the author to end it with a proper finale. Four volumes is quite usual for a yuri series that did well but not enough to remain in the top ranking or and of course in selling terms. A shame truly, this was a heart-warming series that didn't waste any time and didn't make the confession the end, instead they were asked to participate in trials to prove that their love was the strongest bond in the school.