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

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 | 7 |
| Attack | 192 |
| Fire | 140 |
| Slots | 2 |
| Table price | 7,350z |
Upgrades
| Upgraded from | Kut-Ku Stave III |
|---|---|
| Upgrades into | Blue Kut-Ku Stave II, Wolf Bow |
Can also be made new at the smithy.
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.
Materials
Blue Kut-Ku Cpc ×4, Lunastra Shell ×4, Hrd Monster Bone ×4, Inferno Sac ×4