ULTRA Super Saiyan Son Goku can be fully boosted using the dedicated Rising Soul and Super Soul of the Rare Medal Exchange.The required rare medals are 46440 for Rising Soul and 2800 for Super Soul.
Red Rising Soul and Super Soul are also used, so if necessary, exchange them at the adventure book event exchange.
Since the rare medal was left unattended, I was able to fully boost it using about half of my hand.
Can anyone please tell me how to collect rare medals at a high rate?