[5] Kubo's second book, Seiten no mayoikujira (晴天の迷いクジラ), a story about three people who travel to see a stranded whale, was published by Shinchosha in 2012.
[7] Several books followed, including the linked story collection Yoru no fukurami (よるのふくらみ) in 2014,[8] the 2015 novel Sayonara niruvāna (さよなら、ニルヴァーナ, Goodbye, Nirvana), which dramatized an actual case of murder of a young girl by a teenage boy,[9] the 2016 speculative fiction novel Akagami (アカガミ), which imagined Japan in 2030 after rising youth suicide rates and declining fertility,[10] and the 2017 novel Yameru toki mo sukoyaka naru toki mo (やめるときも, すこやかなるときも).
[11] An English version of Kubo's early short story "Mikumari", translated by Polly Barton, was published in 2017 by Strangers Press.
The next year Kubo's novel Jitto te o miru (じっと手を見る), a story about relationships among nursing caregivers, was published by Gentosha.
[15] In 2022, Kubo was awarded the 167th Naoki Prize for her short story collection Yoru ni hoshi o hanatsu (夜に星を放つ, Shooting Stars into the Night Sky).