兄が妹で妹が兄で。
Big Brother is Little Sister and Little Sister is Big Brother
Volumes
| Cover | Vocabulary List | Total | Unique | Used Once | New ⓘ | Density ⓘ | |
|---|---|---|---|---|---|---|---|
| Series | 3,333 | 1,182 | 703 | 59% | 10.27 | ||
 |
兄が妹で妹が兄で。（１） | 1,800 | 752 | 459 | 61% | 752 | 10.84 |
 |
兄が妹で妹が兄で。（２） | 1,533 | 744 | 492 | 66% | 430 | 9.70 |