It seemed like a good idea when I woke up: a day spent hunting the perfect Tokyo cherry blossoms. Here was the plan, drawn up in the first seconds after waking, still in my bed at the Claska Hotel: I’d walk the Meguro-gawa upstream to its source, following the many kilometres of cherry trees that line the banks of the old canal, which links the ocean to Shinagawa and Meguro and which only disappears underground – according to my Tokyo street atlas – north of the Ikejiri-Ohashi train station.

Of course, timing is critical with cherry blossoms. So while I set out feeling confident, I know immediately after turning up onto the pedestrian boulevard that flanks the deep concrete channel where the river flows that something isn’t right. Most of the pink petals are on the ground already. And while the flurries tossed up by the breeze are pretty, they’re also sad. As if the trees, past their manic flowering, were now losing a brief extroversion they’d enjoyed, sobering and darkening, returning to the sedate and orderly shade trees they’d be throughout the summer.

“Great idea to look,” an English speaker tells me when I stop to ask where the city’s peak blossoms might be. “Only sorry, but you’re a week late.”

I’m annoyed with myself. I should have known. I’m mid-way through my experiment with an ultrasimplified mode of travel: no guidebooks, none of my normally obsessive planning. Call it experientialism, what I’m trying. It shares with existentialism a suspicion that reason does not always lead to understanding. But rejecting the isolating bad mood of existentialism, this approach is about blowing life open to opportunities and connections. Believing that we can glimpse understanding in exactly those unplanned moments when we’re just letting life happen.

I’ll acknowledge that the trip has had its moments so far. I’ve been lost more than usual, but the experiences that have floated my way – finding a geocached archive of Tokyoite dreams at the top of a Midtown bank tower or a hidden classical music café in the middle of the Shibuya love hotel district – have carried with them the sense of fate. As if, for being unplanned by either me or by a sales strategy aimed at me, they were more authentically my own. Meant to happen; meant to happen to me.

Now I’m standing opposite the pristine white smokestack spire of the Meguro Incineration Plant and wondering. Clearly, only those who planned ahead this year got to see the damn blossoms.

I carry on toward the source. It’s only two kilometres before the blue line marking the river on my map goes capillary thin, then vanishes in Ikejiri. I cut up through Meguro, past the tennis courts and designer boutiques. Up through Nakameguru, past the modelling shoots, a woman holding blue Cellophane in front of her face as the flash strobes. Just before the booming overhead crossing at Ikejiri-Ohashi station, I pass graffiti that reads “King Wylo Was Here.” And I press on, certain the source is near. But when I reach the road, the river disappears under a tangle of construction equipment and scaffolding. On the far side, only an ornamental trickle remains, idling up between the Ikejiri condos for another few blocks before expiring with an apologetic rustle under a purple hedge.

Now here’s something wholly unplanned: I head back to the hotel. To the soothing vibe of the Claska lobby, where I sit and read a magazine for awhile. The DJ is spinning “Music for a Found Harmonium.”

I regroup. I phone a friend’s Tokyo cousin whose number I’ve been carrying around. He suggests I ride the Chuo Line. Simple as that. “From the centre out into the wilds,” he says.

Here’s all I learned from the web before leaving (not planning, just checking): The Chuo Line runs west from Shinjuku station, one of the oldest JR lines in the system, out through Nakano, Koenji, then on to Kichijoji, where Inokashira Park may be found, with its lake and paddleboats and its shrine to the bitch-goddess Benzaiten, who’s apparently so jealous, it’s bad luck to enter her shrine (and the park as a whole) with a new girlfriend.

So I bump and roll westward, leaving the Shinjuku neon behind. I notice the kids getting on between Nakano and Koenji. Plaid shirts and wallets on chains, a guy with dreadlocks tied up in a tam. All heading somewhere. So I pick one of them and follow – a new waver in Converse high-tops and white-framed sunglasses lugging a guitar and an amp. He disembarks with the crowd in Kichijoji, where I lose him in the station throng.

Japan might be the refined minimalism of teak lobbies and clean lines, but on a hot Saturday in a Tokyo park, it’s like 1,000 inner performance artists have been born all at once.

No matter. Once in Inokashira, down past the flea market stands and the fragrant smoke of outdoor grills ready for the lunch trade, it’s hard to miss what’s going on. Japan might be the refined minimalism of teak lobbies and clean lines, but on a hot Saturday in a Tokyo park, it’s like 1,000 inner performance artists have been born at once. And then, it’s maximalism all the way.

Here’s a dude doing clog dancing and another man dancing in a skeleton suit. Artists sell pastel scribbles and sculptures made of wire and beer bottles melted into vases. There are magicians and balloon tiers and a roster of amateur musicians who cycle in and out of the performance spaces in the dusty square, just north of the lake, as lovers ply the water and ignore Benzaiten. Two bands compete during the time I hang out. There’s the leathery old-timer called Broom Duster playing country on a National guitar. Blue jeans, no shirt, cowboy hat, a mini-amp hanging around his neck blasting out his rendition of “Your Cheatin’ Heart” while some monster yakuza tattoo billboard squats nearby with his five Irish terriers all barking at once.