First connector, second connector, and connector assembly

A first connector to be detachably assembled with a second connector, comprising:

• a first terminal member having a tip side extending in a first direction;
• a first connector housing for holding the first terminal member;
• and
• a slide member held in the first connector housing,
• the slide member being slidable with respect to the first connector housing between a closing position located on an end part in the first direction and an opening position located on an end part in a first opposite direction opposite to the first direction,
• the slide member including a lateral protection wall portion projecting further in the first direction than the first terminal member while being separated from the first terminal member and covering the first terminal member in a direction orthogonal to the first direction in the first terminal member at the closing position, a front protection wall portion for covering a tip opening of the lateral protection wall portion and a terminal insertion hole provided through the front protection wall portion to allow insertion of the first terminal member, and
• the first terminal member being inserted through the terminal insertion hole of the slide member and projecting in the first direction from the front protection wall portion with the slide member moved to the opening position.