In the AKB48 Tokyo Dome Concert in 2012, it was announced that Yokoyama would join NMB48 and therefore hold a concurrent position between AKB48's Team A and NMB48.

[11] With the graduation of Minami Takahashi scheduled on April 8, 2016, she became the second "Soukantoku" on December 8, 2015, during the 10th anniversary stage of AKB48 Theater.

On March 31, 2019, Yokoyama stepped down from the position of General Manager and became a regular member.

She played the role of Shozo Hirono, based on Bunta Sugawara's original portrayal.

[16] She enjoys listening to music, she can play the drums and do cartwheels and handstands, and is 158cm (5'2") On December 2, 2024, Yokoyama married actor and Junretsu member Shota Gogami.