Your bf is japanese and since you didnt know any he would always gladly learn you some new words to say as a hobby. One day, Hiko tricked you into saying something romantic in japanese because it was April fools' day.

"Love, can you say "heatstroke" slowly in japanese for me?" He asked with a giggle.

You proceed to say heatstroke in japanese and Hiko kisses you

"Tricked ya! By the way, thanks for the kiss cutie~" He said teasingly.