2012: two-year-old season

Lovely Day began his racing career by winning a maiden race over 1800 metres at Kokura Racecourse on 19 August 2012. Four weeks later at Hanshin Racecourse he followed up in the Nojiku Stakes over the same distance, beating Sammaru Home.^[6] In November he was dropped in distance but moved up in class for the Grade II Keio Hai Nisai Stakes over 1400 metres at Tokyo Racecourse and finished second of the sixteen runners behind A Shin Top. On his final appearance of the season the colt contested Japan's most prestigious race for juveniles, the Grade I Asahi Hai Futurity Stakes over 1600 metres at Nakayama Racecourse in December and finished seventh, four and a half lengths behind Logotype.^[7]

2013: three-year-old season

As a three-year-old in 2013, Lovely Day failed to win in seven starts. After finishing fifth in the Grade III Arlington Cup on his seasonal debut he finished down the field in the Grade III Mainichi Hai and the Grade I Satsuki Sho before running seventh behind Kizuna in the Tokyo Yushun. He was then matched against older horses and finished second to the six-year-old Meisho Naruto in a handicap race at Kokura in August. After a three-month break he returned to finish second to Curren Mirotic in the Grade II Kinko Sho at Chukyo Racecourse and ended his season by finishing twelfth behind his stablemate Orfevre in the Arima Kinen.^[8]

2014: four-year-old season

Lovely Day began his third season by finishing third in the Group III Chunichi Shimbun Hai at Chukyo. He was then dropped in class and recorded his first victory in nineteen months when he won the Metropolitan Stakes over 2400 metres at Tokyo on 26 April. The horse failed to reach the first three in his remaining four races that year: he finished fifth in a handicap at Tokyo in June, sixth in a similar event at Fukushima Racecourse in July, fifth at Tokyo in November and fourth to Last Impact in the Kinko Sho in December.^[6]

2015: five-year-old season

Having won only one minor race in the last two seasons, Lovely Day began the 2015 season in the Grade III Nikkan Sports Sho Nakayama Kimpai over 2000 metres at Nakayama on 4 January. Ridden by the Irish jockey Fran Berry he recorded his first important victory as he defeated Logotype by one and a quarter lengths in a record time of 1:57.80.^[9] On 15 February at Kyoto Racecourse he started third favourite behind Harp Star and Kizuna in the Grade II Kyoto Kinen over 2200 metres. Ridden for the only time by Keita Tosaki he overtook the pace-setting Suzuka Deevious to win a nose with Kizuna a neck away in third.^[10] His trainer commented "This was an ideal race for him today. He got a smooth run after a good break, and held on during a strong duel".^[11] In his next two races he finished sixth behind Gold Ship in the Hanshin Daishoten and eighth behind the same horse in the spring edition of the Tenno Sho.

On 6 June Lovely Day was partnered by Yasunari Iwata when he contested the Naruo Kinen over 2000 metres at Hanshin and started 3/1 second favourite behind the six-year-old Air Saumur who had won the race in the previous year. He won by two lengths from Majesty Hearts, with Azuma Shuttle taking third ahead of Air Saumur.^[12] Twenty-two days after his win in the Naruo Kinen, Lovely Day returned to Grade I class for the first time since 2012 when he contested one of Japan's most prestigious races, the Takarazuka Kinen over 2200 metres at Hanshin. Gold Ship started favourite ahead of Lachesis (Queen Elizabeth II Commemorative Cup), Nuovo Record (Yushun Himba), One And Only (Tokyo Yushun) and Curren Mirotic (Kinko Sho) with Lovely Day the 13.2/1 sixth choice in a sixteen-runner field. The other runners included the 2014 Kikuka Sho winner Toho Jackal. Ridden by Yuga Kawada, he overcame a wide draw to take the lead 200 metres from the finish and recorded his first success at the highest level as he won by a neck from the five-year-old mare Denim And Ruby with the outsider Shonan Pandora taking third ahead of Toho Jackal.^[13] After the race Kawada commented "I was able to position him behind the front-runner with ease, as the pace was slow, and tried to race him with good rhythm. I was a bit worried about the track, but he responded really well. I was aware of the mare closing in and prayed that he could fend her off".^[14]

After a summer break, Lovely Day returned to action in the Grade II Kyoto Daishoten on 12 October. He was again partnered by Kawada and started 2.1/1 favourite against nine opponents. Lachesis, One And Only and Curren Mirotic were again in opposition, but his most serious rival in the betting was Sounds of Earth who had finished runner-up to Toho Jackal in the Kikuka Sho. Lovely Day recorded his third consecutive victory as he won by one and a quarter lengths from Sounds of Earth, with Curren Mirotic half a lengths away in third.^[15] On 1 November Lovely Day, ridden by Suguru Hamanaka started 2.4/1 favourite for the autumn edition of the Tenno Sho over 2000 metres at Tokyo Racecourse. Old rivals in the field were Shonan Pandora, Last Impact, One And Only and Curren Mirotic whilst the other contenders included A Shin Hikari (Mainichi Okan), Decipher (Sapporo Kinen), Isla Bonita (2014 Japanese champion three-year-old colt), Spielberg (winner of the race in 2014) and the three-year-olds Ambitious and Satono Crown (third to Duramente in the Tokyo Yushun). Lovely Day raced in fourth before moving forward on the final turn and taking the lead in the straight. He defeated the fast-finishing outsider Staphanos by half a length, with Isla Bonita taking third ahead of Shonan Pandora and Ambitious.^[16] His trainer Ikee commented "We still have future races to think about so he wasn't completely tuned up, but for a second autumn start, he was in good form. The horse has developed beautifully and has entered his prime. We have the Japan Cup in mind as his next start. We'll carefully prepare him race by race".^[17]

For his last two races of the season, Lovely Day was stepped up in distance to contest the Japan Cup over 2400 metres and the Arima Kinen over 2500 metres. In the Japan Cup at Tokyo Racecourse on 29 November he started favourite in an eighteen-runner field which included challengers from France, Britain and Germany. In a closely contested finish he was beaten into third place by Shonan Pandora and Last Impact. In the Arima Kinen on 27 December he started second choice in the betting behind Gold Ship. In another close finish he came home in fifth place behind Gold Actor, Sounds of Earth, Kitasan Black and Marialite, beaten less than two lengths by the winner.

2016: six-year-old season

Lovely Day remained in training at six and began his campaign in the Shinkei Osaka Hai on 3 April. He started the 2/1 favourite and finished fourth behind Ambitious, Kitasan Black and Shonan Pandora. He was then sent to Hong Kong for the Queen Elizabeth II Cup on 24 April and started the 1.9/1 favourite. He was sent into the lead from the start by the locally based jockey João Moreira but was overtaken in the straight and finished fourth behind Werther, Military Attack and Blazing Speed. Lovely Day returned to Japan and in June he attempted to repeat his 2015 success in the Takarazuka Kinen. Starting at odds of 10.6/1 he tracked the leaders for most of the way but was unable to quicken in the straight and finished fourth behind Marialite, Duramente and Kitasan Black.

After the summer break, Lovely Day returned in the Kyoto Daishoten on 10 October and finished a close third behind Kitasan Black and Admire Deus. In the Tenno Sho he ran disappointingly and came home unplaced. On his final start he ran for the second time at Sha Tin Racecourse in Hong Kong and finished fourth to Beauty Only in the Hong Kong Cup on 11 December.