Li Chun (李纯), also known by her stage name Junjun (ジュンジュン), and now legally named Zheng Chun (郑纯) was a Japanese pop singer and idol managed by Up-Front Agency and part of Hello! Project. She was an eighth generation member of Morning Musume.
- Chinese Name: Lǐ Chún (pinyin), 李純 (traditional), 李纯 (simplified)
- Legal Name: Zheng Chun (pinyin) 郑純 (traditional) 鄭纯(simplified)
- Stage Name: Junjun (ジュンジュン) (2007–2010)
- Nicknames: JJ, Junko (ジュンコ) Banana Jun, Jun-chan, Panda
- Birthday: February 11, 1988
- Birthplace: Yueyang, Hunan, China
- Blood type: O
- Height: 168 cm
- Skills: Piano, making people laugh
- Hobbies: Music, dance, shopping
- Motto: Even if it's hard, don't give up on your chosen path. Keep on walking, and with great effort, you'll surely create a miracle.
- Favorite food: Fruit, yakiniku
- Favorite words: Smile
- Favorite colors: White, pink, black, red
- Hello! Project groups:
- Morning Musume (2007–2010)
- Wonderful Hearts (2008–2009)
- Zoku v-u-den (2009–2010)
- Muten Musume (2010)
- Ex-ceed! (2010)
In 2006, Junjun participated in the Super Girl Contest, making it into the top 50 of the Changsha region, but did not win. She and the losing other contestants were contacted by Tsunku to participate in the Morning Musume auditions held in Beijing, China. In March of 2007, she and Linlin would join Morning Musume as members of the eighth generation, thus making them the first members of the group to come from outside Japan. They made their concert debut on May 6, 2007 at Morning Musume's 2007 Spring concert tour. On August 8, 2010, it was announced on Tsunku's blog that Junjun, Linlin, and Kamei Eri would graduate from Morning Musume.
On December 15th, 2010, Junjun, along with fellow members Linlin and Kamei Eri, graduated from Morning Musume and Hello! Project on the final date of their autumn Rival Survival tour. The concert, held at Yokohama Arena, was broadcast live in 3D.
On November 3rd, 2014, Junjun had gotten married to Chinese Music Producer, Zheng Nan.
-  Keitai Deka The Movie 3: Morning Musume Kyuushutsu Daisakusen! ~ Pandora no Hako no Himitsu~ (ケータイ刑事 THE MOVIE3 モーニング娘。救出大作戦！～パンドラの箱の秘密)
-  Love in a Second (爱一秒)
-  FāngZhōu (Wei Movie)
- TV Programs
- [2007–2008] Haromoni@ (ハロモニ@)
- [2007, 2008] Tunnels no Minasan no Okagedeshita (とんねるずのみなさんのおかげでした) (2 episodes)
-  Berikyuu! (ベリキュー!)
- [2008–2009] Yorosen! (よろセン!)
-  FUJIWARA no Arigatai to Omoe! (FUJIWARAのありがたいと思えッ!) (3 episodes)
- TV Dramas
-  Hanbun Esper (半分エスパー)
-  Perfect World (完美世界)
-  Dreaming Places Makes Us Dream
-  Cinderella the Musical (シンデレラ the ミュージカル)
-  Fashionable (ファッショナブル)
- As shown on Haromoni@, she loves bananas and will do anything for them.
- Her favorite artists include Wayne Lin, Jun Jie, and Cyndi Wang.
- She is at beginner level in English.
- In recent concerts, she would often argue with Kusumi Koharu during MC corners. Kusumi had stated, however, that it was these MC corners that broke the ice between them as they previously did not talk much outside of work.
- She and Tanaka Reina share a close relationship. They will often go out alone together (on what Junjun has jokingly referred to as dates) and Junjun stated in a DVD magazine that she feels like Tanaka's "boyfriend".
- Junjun enjoys being "gross", and often asks "Am I gross?" or "Was that gross?" after doing something humorous.