TOUGH―タフ―
Tough
    Volumes
| Cover | Vocabulary List | Total | Unique | Used Once | New ⓘ | Density ⓘ | |
|---|---|---|---|---|---|---|---|
| Series | 4,745 | 2,082 | 1,357 | 65% | 7.88 | ||
|   | TOUGH―タフ― 1 | 1,618 | 922 | 658 | 71% | 922 | 8.47 | 
|   | TOUGH―タフ― 2 | 1,589 | 864 | 618 | 71% | 610 | 7.75 | 
|   | TOUGH―タフ― 3 | 1,538 | 919 | 689 | 74% | 550 | 7.43 | 


