Zhan Wei Kai (詹威凱)/David is the eldest son of ZhanFamily and an additional protagonist of The Sound of Happiness. He was responsible for apprehending HongJie, where he becomes close friends with ZhiMing and ZhengHao, and TianYu for their crimes and also restored JiaXiu's confidence towards love.
His popular nickname David is translated as the following:
- Chinese: Da Wei (大衛), which is prounced similiarly but different wording as DaWei (大為).
- Hokkien: Cha Mi (茶米), please note that said translated is unofficial and that's what viewers sometimes referred WeiKai as.
Taught by BaoZhu, WeiKai upheld the principle of optimism and was a vital factor that attributed to his successes and recognition from his peers when handling criminal cases. He earns respect and frustrations from them, as WeiKai often goes against the instructions given by his superiors. He prefers cracking mysteries through his humorous demeanor as a form of entertainment. Despite that, he puts the importance of law above his relationship with his family and friends.
Outside of his job, WeiKai is capable of cheering up the mood of others when they're feeling down, giving warmth when JiaYun was devastated from the ambiguous fate of her husband. While he seems hesitant in showing his feelings of JiaXiu but confirmed that he only sees YongQi (Zhou) as a younger sister he intended to protect. After realizing JiaXiu shared a fondness of art like him since their childhood, WeiKai subsequently dedicated his entire life to give JiaXiu happiness, who fully accepted his love by the end of the drama and completely healed her wounded heart from the past relationship with TianYu.
While maintaining good terms with KunMao, WeiKai doesn't agree with his father's irresponsible attitude towards the marriage with BaoZhu and hence, he harbored an intense hatred and looked down on BaLa as fully responsible on all the sufferings brought towards BaoZhu. Once knowing BaLa is his biological mother, WeiKai immediately understood her pain in the decision of leaving him in ZhanFamily and the failure of taking care of him personally as well as her intentions of not wanting to further hurt said family. With that, WeiKai forgoes any form of resentment towards his biological parents.
- Father: Zhan Kun Mao
- Mother: Du Ba La
- Adoptive mother: BaoZhu
- Younger Brother: Yin Jun Nan
- Step-mother: Cai Yun Ru
- Younger Sister-in-law: Li Bao Na
- Younger cousin: Ah-V
Wu Family (adoptive)
- Parents: Wu Guo Hui, Ceng Mei Ru
- Sisters: Wu Jia Xuan, Wu Jia Wen, Ceng Huan Huan
- Younger Brother: Wu Jia Long
- Elder; adoptive sister and sister-in-law: Wu Jia Yun
- Elder brother-in-law/ex archenemy: Zhang Zheng Hao
- Adoptive nephew: Zhou Jia Mai
Lin Family (biological)
- Parents: Lin Qing Long, Xie Bao Xiu
- Step-mother:Yao Ming Zhu
- Elder brothers: Liu Tian Ding, Lin Zhi Ming (paternal)
Jin Yong Jian (maternal, and elder brother-in-law)
- Younger brother-in-law: Lin Zhi Wen
- Elder sister-in-law: Wang Yan Xi
- Younger sister, elder sister-in-law:Lin Shan Shan
- Grandmother: Yang Ah Mei
- Aunt: Lin Luo Shi
- Uncle-in-law: Qian Jin
- Shen Fang Zi
- Wang Shi Chang
- Zhou Yong Cheng
- Zhou Yong Qi
- Zhou Rui Yuan
- Jiang Yong Qi
- Cai Fu Gui and Chen Yue Xia (via association with YunRu)
- Xu Pei Qi
- Luo Guan Ting
- Luo Hui Lin
- Zhao Dora
- Jiang Can Tang
- Wang Shi Chang
- Chen Yu Yan
- Lin Xiao Ke
- Cai Chong Ren
- Liu Ah Yi
- Zhang Hui Xin (by association with LinFamily)
- Ye Qing Gong
- WeiKai has (24) ex-girlfriends.
- His birthday is recorded as 7/1/1977, putting WeiKai at least 41 years old.