JNT has certainly copied the practice, like
徳田明梨/TOKUDA Akari that sparred with Ito exclusively as well as
Yoshimura Maharu and HAMADA Kazuki at WTTC 2024 or Idesawa at Paris 2024. Similarly and even earlier for KNT, they recruited former CNT players as sparring partners that eventually became their national team members (
1,
2).
Yoshimura Kazuhiro, the younger brother of Yoshimura Maharu and brother-in-law of Kihara, made a guest appearance along with Miwa in the episode of Table Tennis Japan that aired on 2024/8/24. Along with
坪井勇磨/TSUBOI Yuma, they served as the exclusive sparring partners of Hirano ahead of and during Paris 2024, doing whatever drills at her request. Ito also recruited at least 2 male players to serve as sparring partners ahead of Tokyo 2020.
ITTF世界卓球選手権釜山大会(団体戦)
https://jtta.or.jp/tour/11136
Sparring partners
YOSHIMURA Maharu (TEAM MAHARU)
HAMADA Kazuki (Waseda University)
NAGASAKI Miyu (Kinoshita Group)
I Ayano (Chugoku Electric Power)
Parent staff
OKA Yusuke (Nippon Life Insurance)
JIN Huimei/KIN Hoimei (Nippon Life Insurance)
ZUO Junqi (Nippon Life Insurance)
HAYATA Yasue (Individual)
ITO Minori (Starts)
MASHIKO Sayuri (ELJ)
TOKUDA Akari (Kansai University)
ZHANG Cheng (Athlete Solution)
HARIMOTO Yu/Zhang Yu (Sendai Junior)
PANG Bin (Kinoshita Group)
XUE Yunchao (Kinoshita Group)
第33回オリンピック競技大会(2024/パリ)
https://jtta.or.jp/tour/25524
Sparring Partners
JIN Bo? (Japan Table Tennis Association)
YOSHIMURA Maharu (SCO Group)
HAMADA Kazuki (Waseda University)
MORIZONO Masataka (BOBSON)
KIZUKURI Yuto (Kansai Table Tennis Academy)
IDEZAWA Kyoka (Senshu University)
Parent Staff
OKA Yusuke (Nippon Life Insurance)
JIN Huimei/KIN Hoimei (Individual)
ZUO Junqi (Individual)
HAYATA Yasue (Individual)
NUMAZAWA Shun (Individual)
NAKAZAWA Rui/WANG Rui (Kinoshita Group)
HARIMOTO Ryo/Zhang Ling (Harimoto Sendai Junior)
YOSHIMURA Kazuhiro (Careritz & Partners)
TSUBOI Yuma (FPC)
And the Japanese media certainly have their share of stereotypes, opting to refer to CNT's sparring partners as コピー選手/copy players.
平野美宇の“コピー選手”が“本家超え” 中国16歳が下剋上V「似てるところある」
(Hirano Miu's "copy player" surpasses the original: 16-year-old from China rises to victory, "There are similarities")
https://the-ans.jp/news/5300/
なぜ中国は卓球が強いのか?<Vol2.邱建新> (Why is China so good at table tennis? <Vol.2. Qiu Jianxin>)
https://rallys.online/person/player-voice/china02/
Are there really copy players?
--Does China take any special measures after losing?
Qiu: Not really. They simply get stronger because they practice more and the quality of their practice is high. They don't practice just to beat Harimoto. Of course, they watch videos of their opponents and make strategies before the match.
--I often hear about the creation of copy players as countermeasures.
Qiu: That's often said, and it used to be the case in the past. But now, especially with the men, it's rare. If a player could copy Tomokazu, that player could become a representative for the WTTC (laughs). If it's a female training partner, you might be able to create a male copy of the player, like a Mima Copy. But it's hard to copy a top man. For example, is there a copy player for Mizutani? Lin Gaoyuan? Wang Chuqin?
--It's true, they're completely different (laughs).
Qiu: (Mizutani) Jun's serve is impossible to imitate. If a Chinese player could imitate Tomokazu's backhand, he would definitely be playing for the national team, not just a practice partner.