TEN saves DOYOUNG’s number in his phone as Kim Dongyoung.
It was revealed by HAECHAN that TEN was with them in the trip DOYOUNG brought the underage trainees including him, JAEMIN, and JENO to Han river in their training days.[1].
In Official NCT U Vyrl Profiles by TEN and DOYOUNG, they wrote to each other in their profile.
To TEN, DOYOUNG is "a friend with completely opposite personality, whom I need!"
To DOYOUNG, TEN is "a friend that I can joke around with ㅋㅋ"
During NCT U Pangyo Fansign on May 5, 2016, TEN apologized to fans for his poor Korean but DOYOUNG commented that TEN speaks fluently whenever they are arguing.
In Enter-K interview aired on May 29, 2016, members were asked how would it be without one of them. JAEHYUN answered that if there was not DOYOUNG, it would not be DOYOUNG and TEN duo. He added that they look like a very close friend being playful to each other when they are fighting.
In SMTOWN official Japan NCT Q&A, TEN chose DOYOUNG as a member who takes care the others most.
They won 2016 SM BABY AWARDS's Best Harmony Award for members who provided the fans humors in the best harmony in 2016[2].
TEN once called DOYOUNG "Jinguz/Jingoos" which is a misspelling of chingu (친구 in Korean means a friend of the same age). Jinguz later became a group name for NCT's 96-line which including KUN, DOYOUNG, and TEN.[3].
DOYOUNG gave away the present he got from NCT Fanparty 2018 to TEN.[4]
On August 13, 2020, TEN mentioned DOYOUNG during WayV Video Fansign event that they are keeping each other in touch but never get a chance to go out together recently because DOYOUNG was busy every time he texted him. Earlier in WayV Busan fansign on January 4, 2020, TEN mentioned they planned to have a meal together but he could not make it himself.
On January 9, 2021, DOYOUNG answered to a fan's question in Yizhiyu Video Call Fansign event that he chooses five-years-old TEN over five TENs because the latter would be too tiring for him. Later on January 30, 2021 during the following event, TEN told a fan that he would choose five-years-old DOYOUNG over five DOYOUNGs so he can tease him as a little brother.
