Composed in July 1917, consecutively with "Seifuku 2." It is dedicated to Etsuko Terasaki. The European title does not contain the word "Seifuku," being simply "Petit poème." Although no clear documentation regarding the origin of the Japanese title "Seifuku" has been found, it appears to be related to the birth of his eldest daughter in April of the same year. Although Yamada had experienced troubles related to women and marriage before marrying his wife Kikuo in November 1916, Misa, born just before the composition of this work, was his first biological child. Imagining his great joy as a father, it suggests that the Japanese title is linked to her birth. If the word "Seifuku" is interpreted literally, it can mean "holy," "happiness," or "blessing." Therefore, it can be inferred that this title expresses the father's joy at being blessed with his first child and his perception of the birth of life as "sacred."

The work was promptly premiered in October of the same year, performed by the composer himself. Furthermore, Yamada's series of "Petit Poèmes" are described as "short pieces that learned from Scriabin's style and often have private titles" (Nobuko Goto, "Yamada Kōsaku," edited by Kunihiko Shimonaka, Ongaku Daijiten Vol. 5, Tokyo: Heibonsha, 1983, p. 2619). The style of "Seifuku 1" is likely no exception.