Joogeun is not a member of SHINee. He is a toddler that the boys of SHINee took care of for "Hello Baby!" Season 2.
When the baby first came out, everyone was convinced that the baby was Minho's due to their uncanny resemblance especially in the eye area.
At the end of the season, they said a tearful goodbye to the child who already had a great relationship with them.
Minho is still in contact with Joogeun.