This mineral is called ulexite and has special optical properties.

He succeeded in a difficult project with the spirit of 'ishi no ue ni mo sannen', which means great works are performed by perseverance.

We are aiming to kill two birds with one stone with this plan.

His words held a double surprise, like 'isseki-rokuto'.

He is truly a person who embodies the saying, 'A man of virtue will naturally attract admirers.'