August 2025: Top New Releases on Billboard Japan Hot 100

The last breath of summer turned into a sprint for Japanese music. August 2025 saw a rush of brand‑new songs muscling their way onto the Billboard Japan Hot 100.

Each release came with its own story. A polished idol group celebrated a milestone single. A boy group conjured mythical creatures. A fresh band brought a TikTok‑driven summer anthem. In this post, I chart the month’s new releases that reached the chart. I explain who these artists are. I offer a candid look at how fans responded.

Songs Released in August 2025 and Their Chart Performance

Song	Artist	Release date (digital / physical)	Chart high on Japan Hot 100	Public reaction (sales/streams)
What We Got Kiseki wa Kimi to / I Know	King & Prince	6 Aug 2025 (digital EP)	No. 1 (week of 13 Aug)	Sold ~331 k physical copies in first week; trending widely as the Mickey‑Mouse‑theme song
Summer Shadow	Mrs. GREEN APPLE	11 Aug 2025 digital single	No. 2 (week of 27 Aug)	Part of a five‑month release streak and tied to Kirin Gogo no Kocha commercials; strong radio airplay and TikTok challenge
U.M.A. / Mikakunin Ryōiki	Number_i	11 Aug 2025 digital single	No. 1 (week of 20 Aug)	Fans embraced the R&B–hip‑hop infusion; pre‑release buzz for the September album No.II
Count to Love	BoyNextDoor	18 Aug 2025 (digital), 20 Aug 2025 (CD)	No. 1 (week of 27 Aug)	Debuted with 431 k CD sales and high radio airplay; first Japanese No. 1 for the Korean group
Sparkle Summer	KID PHENOMENON	20 Aug 2025 (CD); pre‑release 8 Jul 2025	No. 4 (week of 27 Aug)	Idol group’s summery single pre‑released digitally; charted strongly on release week
YAKIMOCHI / Good Job!	SWEET STEADY	Digital single YAKIMOCHI on 11 Jun 2025; CD single YAKIMOCHI / Good Job! on 20 Aug 2025	No. 5 (week of 27 Aug)	Physical release included multiple editions; fans praised the contrasting themes of jealousy and encouragement
Chōzetsu SUMMER de Baka ni Nare (“Be Stupid in Super Summer”)	Lienel	20 Aug 2025 CD single	No. 7 (week of 27 Aug)	Campaign events at HMV and other record stores built hype around the energetic anthem; limited editions sold quickly

Note: The chart numbers refer to the Billboard Japan Hot 100 rankings for August 2025. Songs like “Same Numbers” by Nogizaka46 (released 30 Jul 2025) topped the 6 Aug chart. Nevertheless, they are outside the scope of August releases. Hence, they’re not covered here.

Artist Spotlights and Story Behind Each Track

King & Prince – “What We Got Kiseki wa Kimi to / I Know”

For their 17th single, J‑pop royals King & Prince delivered an unabashedly upbeat theme for Mickey Mouse. The five‑member group is renowned for their choreography and harmonies. They fused bubble-gum pop with disco horns. They included Japanese lyrics that celebrate serendipity in their music. The single debuted at the top of the Hot 100. It sold 331 thousand CDs in its first week. This proves that physical media still matters. Public reaction was enthusiastic. Families shared dance covers on social media. The song’s tie‑in to Disney’s centennial celebrations kept it ubiquitous on television. Some critics noted that the group’s sound hasn’t evolved much. Yet, fans praised the cheerful energy. They said the track felt like summer itself.

Mrs. GREEN APPLE – “Summer Shadow”

Pop trio Mrs. GREEN APPLE continued their five‑month run of new songs. Their latest is “Summer Shadow,” a breezy track built around shimmering guitars. It also features nostalgic lyrics. Released on 11 August 2025, the song was featured in Kirin’s Gogo no Kocha adverts. Its success proved how commercial tie‑ins can fuel a hit. It peaked at No. 2 and maintained heavy airplay. Fans launched a TikTok challenge using the hashtag #夏の影, and the campaign spurred thousands of user‑generated videos. Some listeners felt the band was playing it safe after their darker single “Kusushi‑ki.” Others appreciated the lush summer imagery. They saw it as the soundtrack to lazy afternoons.

Number_i – “U.M.A. / Mikakunin Ryōiki”

Boy‑band Number_i is composed of Sho Hirano, Yuta Jinguji, and Yuta Kishi. They continue to carve out a niche blending J‑pop with R&B and hip‑hop. Their single “U.M.A.” is an acronym for Unidentified Mysterious Animal. It arrived on 11 August 2025. This makes it the lead track for their upcoming album No.II. With funk bass lines and a rap verse referencing cryptids, it shot straight to No. 1 on the chart. Critics admired the adventurous production. Fans trended #UMA on X (Twitter). They speculated about the mythical creatures referenced in the lyrics. The track’s success hints at the momentum behind the trio’s September album. Their earlier EP GOD_i already racked up millions of streams.

BoyNextDoor – “Count to Love”

Korean act BoyNextDoor, though not Japanese, scored the month’s final No. 1 with their Japanese single “Count to Love.” The six members are Sungho, Riwoo, Jaehyun, Taesan, Leehan, and Woonhak. They debuted in 2023 under KOZ Entertainment. They are known for portraying everyday teen romance. “Count to Love” pairs a snappy pop beat with counting‑game lyrics that make it instantly catchy. The single was released digitally on 18 August. It was released physically on 20 August 2025. It moved over 431 thousand CDs and dominated radio play. Japanese fans applauded the group’s Japanese pronunciation. They appreciated the fresh concept too. Some veteran J‑pop observers, though, lamented that domestic acts were being out‑sold by a Korean group. Still, there’s no denying the infectiousness that propelled this song to the top.

KID PHENOMENON – “Sparkle Summer”

Tokyo‑based idol outfit KID PHENOMENON, a seven‑member group from the EXILE TRIBE lineage, specializes in dance‑friendly pop. Their single “Sparkle Summer” was pre‑released digitally in July. It was issued as a CD on 20 August. This song is an unabashed summer anthem. It features horns and festival shouts. It reached No. 4, partly thanks to an enthusiastic fanbase that organized flash mobs and supported multiple edition purchases. The group, debuting in 2022, shows promise as relative newcomers. Some listeners felt the production leaned heavily on formulas used by their senior groups.

SWEET STEADY – “YAKIMOCHI / Good Job!”

A concept group blending kawaii aesthetics with dance‑pop, SWEET STEADY debuted in 2024 under Asobisystem’s Kawaii LAB. The seven members are Sakina, Mayumi (center), Nagisa, Rise, Natsuka, Yui, and Ayu. They released the digital single “YAKIMOCHI” (meaning “jealousy”) in June. For August they packaged it with a new track, “Good Job!” for a CD single released on 20 August. “YAKIMOCHI” channels the pangs of unrequited love, while “Good Job!” is a cheer song encouraging listeners to pat themselves on the back. The single landed at No. 5 and signalled a growing appetite for the group’s blend of cuteness and empowerment. Some critics called the lyrics simplistic. However, fans praised the members’ vocal growth. They lined up at handshake events to show support.

Lienel – “Chōzetsu SUMMER de Baka ni Nare”

Six‑member dance‑and‑vocal unit Lienel, part of Stardust Promotion’s EBiDAN roster, debuted in April 2023. Their latest single was released on 20 August 2025. The title roughly translates to “Be Stupid in Super Summer.” It was available with several limited editions. Up‑tempo and synth‑driven, it encourages listeners to let go of inhibitions and embrace summer silliness. A promotional campaign took place at HMV, Tower Records, and Shibuya TSUTAYA. This effort boosted visibility. As a result, the single entered the Hot 100 at No. 7. The group’s youthful image and coordinated dances won many hearts. Yet, some reviewers noted that the song lacked a memorable hook. Nevertheless, for a group barely two years into their career, charting alongside veteran acts is a notable achievement.

Final Thoughts

August 2025 proved that Japan’s music scene remains dynamic and diverse. Idol powerhouses like King & Prince and Nogizaka46 continue to dominate physical sales. Newer groups such as SWEET STEADY, HANA, and Lienel are finding their footing. The month also underscored the growing influence of international acts like BoyNextDoor and cross‑genre experiments from Number_i. As the summer fades, these releases offer a snapshot of pop’s present. They hint at where Japanese music is headed next. Enthusiasts should keep an ear out for September’s releases. Albums from Number_i and others are on the horizon. The autumn charts will be just as thrilling.