The Taboo summoner

This is a story of ordinary boy who lacks confidence and always doubts his decisions. except for the time when he confessed his love for his crush and of course it isn't like he suddenly got confidence for confession rather it was the day before summoning test and he wanted to make his feelings clear for her before that but, unexpectedly she agreed and became her girlfriend. Now, two years has passed since that incident and for some reason he didn't took part in that test of summoning which was supposed to be a very important event of one's life and after that he didn't try either and instead decided to became a summoning ground researcher. on this day he suddenly decided to broke up with her girlfriend but, during there argument he suddenly got fainted and so his girlfriend took him to hospital, their she found out that actually he had brain tumor for more than two years and he wouldn't be able to more than few months more. But, what these people didn't understand was that reason for his fainting wasn't tumor rather it was something else