[A-PEN68 Development Log] Episode 8: A Year of Being Hooked on Topwater Fishing for Black Sea Bream

Sunset near Tsukamoto on the Yodo River

My journey into topwater bream fishing started right where most anglers begin today: obsessively scanning for information.

I started by digging up everything I could find on local hotspots like the Yodo and Muko Rivers. I watched every single YouTube video from legendary anglers like Morizo-san, searching "Yodo River Bream" and "Muko River Bream" until my eyes blurred.

“Where exactly are they pulling these fish from?”

“How are they approaching the spot?”

“Where are they positioning their feet on the bank?”

Back in 2023 and 2024, I was starting completely from scratch. It was pure trial and error. I was desperate to figure out the puzzle: How do you trigger a clean bite? What’s the ideal retrieval speed? How much line slack should you leave on the pause?

I’d watch a video, try to mimic it on the water, read a book, go out to the field, and fail miserably. Occasionally, I’d stop by flagship tackle shops or talk to the guys at Top Butler, asking them, "Hey, is this rhythm right?" or "Should I tweak my cadence here?" just to see if I was on the right track.

The frustration was real. I’d get tons of blowups, but no hookups. Just endless short strikes. Refining the A-PEN 68 Prototype

Even though I was constantly doubting myself, I could feel I was right on the cusp of figuring something out. It was during this exact phase of trial and error that we started tweaking the prototype of the A-PEN 68.

Our goal for the A-PEN 68 was specific: keep the internal structure as simple as possible to maximize the air chamber's volume for high buoyancy, yet still pack a heavy, distinct one-knock rattle sound and serious casting weight. We wanted the exact same deep acoustic quality of the larger A-PEN 90, but in a smaller, more buoyant profile. Finding that perfect balance meant endless field testing and micro-adjusting the internal weights. It’s a delicate game—too much or too little, and the action dies.

A test model with repeated, minute weight adjustments. Finding the right balance—not too much, not too little—is quite difficult.

June 1, 2025: The Breakthrough Day

On that morning, I hit the Yodo River with our pro staffer, TK Takuya, to put the latest A-PEN 68 proto through its paces.

We started at first light in front of the apartments and spent the entire morning grinding through the lower river reaches, working the opposite bank near Fuku. Takuya, being the hammer that he is, was getting plenty of action.

But the fish just wouldn't commit.

I had a few blowups myself, but the hooks just wouldn't stick. "Man, so close." "They're tracking it, but just missing the tail."

We walked miles of shoreline, bouncing feedback off each other regarding the A-PEN 68's walking action and casting distance, but the clock kept ticking. By the time the slack tide hit around 2:00 PM, we were beat.

"Let's call it a day," we agreed. At that point, both of our livewells were completely empty. We split up, and I started heading toward my car.

A-PEN90 and A-PEN68 Prototype

"Just One More Cast..."

I looked down at the A-PEN 90 and the A-PEN 68 proto in my box. I just couldn't walk away with a blank card.

"Just one more spot," I muttered to myself.

I drove over and dropped back into the river near Tsukamoto. I started beating the rocky, rip-rap shoreline, walking down toward Juso. This was an area where I’d previously had great reactions on our Neolyn lure, so I told myself, "Just check this one stretch, then go home."

I worked my way upriver, methodically placing casts right along the shoreline structure. Almost immediately, I got a few aggressive bites.

“Okay, they’re definitely here.”

Looking down at my feet, I noticed schools of Haku (mullet young) schooling up and migrating upriver. The baitfish were tightly balled up. “This is the perfect storm,” I thought, picking up my pace upriver.

Then, I spotted it: a section of the rip-rap shoreline where the rocks had collapsed slightly, creating a subtle underwater point that extended out into the current.

I launched a cast just upstream of the structure and began a slow, rhythmic walk-the-dog retrieval. The deep, rhythmic click of the A-PEN 68’s one-knock sound echoed perfectly across the water.

Just as the lure crossed the tip of the rocky point, a dark shadow emerged, tracking right behind it. The fish followed the lure all the way to the bank, inches from where I stood.

“Eat it... eat it...”

I kept my composure, twitching the rod tip to make the pencil bait dance in place right at the water's edge.

BOOM.

The rod loaded up instantly, pinning my blank straight down into the water.

A-PEN68's first ever black sea bream

The Moment It All Clicked

That was the very first black bream caught on the development model of the A-PEN 68.

It was a solid fish, right around 45cm. I didn’t have a tape measure on me, but holding that thick, silver flank, it didn’t matter. After weeks of getting brushed off and missing short strikes, I had finally executed a perfect hookup and landed the fish.

Seeing the entire sequence unfold right at my feet—how the fish tracked the bait, how it made its move, and exactly how it engulfed the lure—was a revelation. It wasn't just a catch; it was a data download straight to my brain.

"The A-PEN 68 is dialed in. This is the exact action they want."

With that single fish, the entire philosophy of "Topwater Bream Fishing" (Chinu Top) clicked for me. It wasn't an intellectual theory anymore—it was muscle memory. From that exact second, I was completely hooked. Through the development of the A-PEN 68, a burning curiosity to dive deeper into the world of topwater light game fishing took root.

That single fish was the catalyst for everything.

But let's pause here for a second. Why the A-PEN 68? Why was I so obsessed with creating this specific 68mm size profile?

It wasn’t just because Kita-san from North Wave suggested it, nor was it simply because I fell in love with topwater bream. When I look deeper into my own roots as an angler, the real origin of this obsession goes back to where I started: Bass Fishing.

In the next journal entry, I’ll take you through [Returning to the Roots: The Design DNA of the A-PEN 68]. Stay tuned.

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