Is Kuroda too 'in love' with his own policies?

Bank of Japan (BOJ) Governor Haruhiko Kuroda is too "in love" with his own policies, according to one analyst who says the confidence could have some negative repercussions.

At the annual Jackson Hole central bankers' retreat in Wyoming at the weekend, Kuroda was reported saying that the aggressive monetary policy action that he has championed to revive the Japanese economy was starting to have an impact.

(Read more: BOJ's Kuroda: Won't hesitate to ease further if downside risks increase)

"Kuroda, who spoke on a panel at Jackson Hole Saturday... is in love with his policies," Axel Merk, president of Merk Investments, told CNBC Asia's "Squawk Box" on Tuesday.

"He was bragging about how his policies are working and he was referring to how the bond yields are holding, whereas they have been spiking everywhere else," added Merk.

(Read more: Should Kuroda be more like Draghi?)

After rising sharply in April and May on uncertainty about the implications of the BOJ's decision to embark on aggressive monetary stimulus, Japanese government bond yields have edged down.

The benchmark 10-year yield is trading around 0.76 percent. In contrast, the 10-year Treasury yield has risen sharply recently to about 2.8 percent in anticipation of a scaling back of U.S. monetary stimulus.

Bank of Japan Governor Haruhiko Kuroda
Tomohiro Ohsumi | Bloomberg | Getty Images
Bank of Japan Governor Haruhiko Kuroda

Aggressive monetary and fiscal stimulus is helping revive the economic fortunes of Japan, the world's third largest economy. Japanese stocks have powered 28 percent higher this year, while the yen has weakened around 13 percent against the dollar, providing a substantial boost to exporters.

Still, Merk said Kuroda's level of conviction could be a risk for Japan's economic outlook because at the first sign that these policies not working, policy makers are more likely to ramp up than revise their policies.

(Read more: Here's the missing piece in Japan's growth puzzle)

He added that policy makers and the central bank governor, confident in their policy action, are unlikely to manage bumps in the road, such as the upcoming consumption tax hike, in the right way.

The tax hike, which is viewed by many as an essential part of tackling Japan's huge budget fiscal deficit, is scheduled to rise from 5 to 8 percent in April, but politicians and industry watchers have recently voiced fears that the tax hike could derail the economic recovery.

(Read more: Sales tax hike is vital and will hurt Japan, says IMF)

"The big thing of course in Japan is now that they are going to increase the value added tax, which is going to slow down the economy and Kuroda, being so convinced his policies are great, is going to double down," he said, referring to a possible ramping up of the BOJ's asset-purchase program.

"As they double down on their policies because they are not going to be as effective as they think, at some point something have to give, yields will go up, the BOJ is going to jump in and over the long run that will be very detrimental for their policies," he said.

"Our long term price target for the yen is infinity, meaning we don't think the yen is ultimately going to survive," he added.

—By CNBC's Katie Holliday: Follow her on Twitter: @hollidaykatie