Shindere Shoujo to Kodoku na Shinigami

Akira, a second year middle school student, has a normal life on an island of solitude, a serene and peaceful school setting. Akira's daily life is shattered one day by the transfer of a mysterious boy; Matsushiro Nishigami who introduces himself as a shinigami with the phrase "Anyone who gets close to me dies". What could be the meaning of such a bizarre introduction?