In 1937 Hayashi went to Tokyo, where he studied at the Oriental School of Photography (オリエンタル写真学校, Orientaru Shashin Gakkō), again under Tamura.

A few months later he moved to Tōkyō Kōgeisha (東京光芸社) in Ginza, where he soon had an unexpected opportunity to demonstrate his unusual command, gained in Yokohama, of flash illumination.

In 1942 Hayashi went to the Japanese embassy in Beijing, with the North China News Photography Association (華北広報写真協会, Kahoku Kōhō-shashin Kyōkai), which he had just cofounded.

While in China he did a lot of work with what was then regarded as a wide-angle lens;[4] this led to his nickname of Waido no Chū-san (ワイドの忠さん, “wide Mr Chū”).

Always gregarious, Hayashi had friends and acquaintances among the buraiha (dissolute writers), and his portraits of Osamu Dazai and Sakunosuke Oda, both taken in the Lupin (ルパン, Rupan) bar, are now famous.

[9] At the end of that year, the literary magazine Shōsetsu Shinchō published the first of Hayashi's series of portraits, titled Bunshi (literati), of chūkan bungaku (中間文学), other writers and figures close to the world of literature, in its January 1948 issue; the series would continue until 1949 and was later collected into an anthology.

Hayashi's portraits show their subjects in context, and the combination of their subject matter and the method by which he took them — by his own account intermediate (chūkan) between the tense, decisive style of Ken Domon and the relaxed, informal style of Ihei Kimura — led them to be termed “intermediate photographs” (中間写真, chūkan shashin).

[10] The series of portraits that he was commissioned to take remained fresh; that of an unposed (and unsuspecting) Jun'ichirō Tanizaki is particularly famous.

[11] Meanwhile, his portraits of orphans and the desperate but sometimes pleasurable life of the city were run in camera magazines, general-interest magazines, and more surprisingly in Fujin Kōron; these too would be anthologized, first in 1980 in a book, Kasutori Jidai (カストリ時代, "The rotgut period"),[12] that has a lasting reputation as a historic document.

It would be seven more years before his second book was published (a pace that was normal at the time), and the photographs that had made him famous in the kasutori period would only be anthologized from the 1980s.

Hayashi's works are displayed by the Shunan City Museum of Art and History in Shūnan, Yamaguchi.