Nani o Shimasu ka: Moshi sekali ga owaru to shitara

The world will be uninhabitable in the future, A shepherd and former Latvian royal sword instructor 'Willy Petelgeuse van Alderbaran Bönaparte' Back to work to save the world, teaches his students who are living weapons that can be easily disposed of, During his teaching days he accidentally fell in love with 'Alexia Van Scarlet'. With him she felt every first experience, sweet cakes, fruits, and all the new things she had never tried, with him she felt the calm and meaning of love, but... Slowly Alexia became more and more distant, while Willy, who was usually close, now seemed strange for some reason, never greeting each other, never together, as if willy was just an exercise book, Will this story end in a field of clay violets?, Will this story end perfectly?