[磨穿铁砚 / 磨穿鐵硯, mó chuān tiě yànㄇㄛˊ ㄔㄨㄢ ㄊㄧㄝˇ ㄧㄢˋ] to grind one's way through an inkstone (成语 saw); fig. to persevere in a difficult task; to study diligently#912119
[すずりあらい, suzuriarai] (n) (obsc) (See 七夕) event where schoolchildren wash their inkstones, brushes and desks the night before Tanabata to pray for success in their studies