Sachiko Matsumoto.
Unnerved, Midori clutched the two letters in her hand as she tiptoed down the stairs. Reaching the bottom, she called out softly, "Mother?"
Yuriko, startled by the unexpected voice, turned. "Midori? I thought you were tucking Ame-chan in."
"She's asleep," Midori replied hesitantly. Then, holding up the letters, she blurted out, "Mother, is Grandmother's first name by chance 'Sachiko'?"
"... Yes. Are those letters...?"
Midori passed both letters to Yuriko. As Yuriko scanned the names scrawled on the envelopes, disbelief painted itself across her face in a series of rapid blinks.
"Oh, my. I..."
She returned the third letter to Midori and said, "You should hand Grandmother this letter, Midori-san. Maybe she will accept it if it comes from you."
Midori pressed her lips together in concern.
"Mother, the content of this letter..."
