We present a Subaru/IRCS H-band image of the edge-on debris disk around the F2V star HD 15115 . We detected the debris disk , which has a bow shape and an asymmetric surface brightness , at a projected separation of 1–3 ” ( \sim 50–150 AU ) . The disk surface brightness is \sim 0.5–1.5 mag brighter on the western side than on the eastern side . We use an inclined annulus disk model to probe the disk geometry . The model fitting suggests that the disk has an inner hole with a radius of 86 AU and an eccentricity of 0.06 . The disk model also indicates that the amount of dust on the western side is 2.2 times larger than that on the eastern side . A several Jupiter-mass planet may exist at \gtrsim 45 AU and capture grains at the Lagrangian points to open the eccentric gap . This scenario can explain both the eccentric gap and the difference in the amount of dust . In case of the stellar age of several 100 Myr , a dramatic planetesimal collision possibly causes the dust to increase in the western side . Interstellar medium interaction is also considered as a possible explanation of the asymmetric surface brightness , however , it hardly affect large grains in the vicinity of the inner hole .