101Leafy researched the games.
Blue Kut-Ku Stave II

Shining fire Bow that unabashedly makes the most of Blue Kut-Ku materials.
An artistic blue bow whose frame makes use of Blue Yian Kut-Ku's coloring. Its fire attacks, at odds with its color, come from the Inferno Sac used in the string. Its power is modest, but its good expandability and its ability to take every kind of coating make it very versatile.
Our translation of 復刻 ハンター大全 (KADOKAWA / Enterbrain, 2014), page 174.
| Class | Bow |
|---|---|
| Rarity | 9 |
| Attack | 240 |
| Fire | 180 |
| Slots | 2 |
| Table price | 41,600z |
Upgrades
| Upgraded from | Blue Kut-Ku Stave I |
|---|---|
| Upgrades into | BlueKut-KuStave III |
Upgrade tree from モンスターハンターポータブル 2nd G 公式ガイドブック (Enterbrain, 2008), page 796.