SoftBank Group Corp.’s Masayoshi Son has bet on everything from chip companies to office-space provider WeWork Inc., but has taken an unusual turn with his latest foray: sleep disorders.

Japan’s Aculys Pharma LLC, backed by SoftBank’s second Vision Fund, has bought the rights to develop and sell pitolisant, used to treat narcolepsy and sleep apnea in Europe. The drug, made by French drugmaker Bioprojet Pharma, is used to treat bouts of involuntary sleep.

The goal of the purchase is to provide solutions beyond selling the medicine, by using wearable devices and analyzing data to treat people, Kazunari Tsunaba, Aculys’s chief executive officer, said in an interview.