"Ashita, Haru ga Kitara" (明日、春が来たら, "Tomorrow, If Spring Comes") is a song by Japanese entertainer Takako Matsu from her debut album, Sora no Kagami (1997).

The track was recorded in Santa Monica, California, and is a mid-tempo J-pop song composed in the key of B minor.

[9][10] At the wrap up party of the drama, the director of the series at that time heard her perform karaoke and suggested that she try singing.

[6] "Ashita, Haru ga Kitara" was written by Yūji Sakamoto and Daisuke Hinata, both of whom had worked with Matsu.

[14] "Ashita, Haru ga Kitara" is a mid-tempo J-pop track with a "gentle melody",[17] that lasts for 4 minutes and 13 seconds.

[18] The lyrics of the song, written from the perspective of a girl, sees her recollect the memories of her love with a member of her high school baseball team and how she hopes to meet him again "tomorrow, if spring comes".

[12][15] Upon the album's release, Yoshitake Maeda, writing for BMG Japan, commented that Sakamoto probably reminisced on his teenage years through the song.

[21] In addition to the two songs, the single also featured the original karaoke track to "Ashita, Haru ga Kitara".

[22] A reviewer for CD Journal commended "Ashita, Haru ga Kitara" for being "pure" and noted that Matsu's "unobtrusive [and] naked voice" is like "sitting in a sunny spot on early spring day".

[17] Similarly, Rolling Stone Japan wrote that the song has a "heartwarming" production, which they noted has become synonymous with Takako Matsu.

[3] Another reviewer for CD Journal said that the b-side, "Zutto... Iyō yo"'s arrangement makes it an "impressive pop song".

[29] In a web poll conducted in 2013 by MyNavi news asking people about their favorite spring song, "Ashita, Haru ga Kitara" was ranked at number 10.

[45] In 2009, Matsu performed the song on the FM802 sponsored event Radio Magic, with Yoshiyuki Sahashi directing the backing band to a crowd of about 12,000 people.

[53] It was also covered for the spring compilation Cafe de Nagareru Sweet Jazz 20 the Best Sakura Songs, which peaked at number 39 on the Oricon albums chart.

The new version titled, "Ashita, Haru ga Kitara 97–07" (明日、春が来たら 97–07) was recorded at the Mouri Art Works Studio in Tokyo.

[6] Its modified lyrics penned by Yūji Sakamoto, the writer of the original song, are meant to convey the emotions of the singer ten years into her debut.

[58] While talking to NHK at the time of the single's release, Matsu commented that the new lyrics not only reflect the changes she had made over the past 10 years, but also of Yūji Sakamoto.

[65] While reviewing Cherish You, Takayuki Saito of HotExpress magazine noted that the track has a "novel" arrangement and Matsu's current voice "calls out" to her "innocent" self of ten years ago.