Tsushima's success in writing was brought to a halt when his idol, the writer Ryūnosuke Akutagawa, committed suicide in 1927. Tsushima started to neglect his studies, and spent the majority of his allowance on clothes, alcohol, and prostitutes. He also dabbled with Marxism, which at the time was heavily suppressed by the government. On the night of December 10, 1929, Tsushima committed his first suicide attempt, but survived and was able to graduate the following year. In 1930, Tsushima enrolled in the French Literature Department of Tokyo Imperial University and promptly stopped studying again. In October, he ran away with a geisha named Hatsuyo Oyama () and was formally disowned by his family.