Investors looking for passive income on the ASX might be finding it harder and harder to bag a decent dividend yield. With the tear that the S&P/ASX 200 Index (ASX: XJO) has been on over the past 12 months or so, many ASX 200 dividend shares have seen their yields drop substantially.

Commonwealth Bank of Australia (ASX: CBA) shares, for example, today boast a yield of just 3.1%. That's rather unusual for an ASX bank stock.

Similarly, Wesfarmers Ltd (ASX: WES) puts up just 2.7% at current pricing.

Even the Coles Group Ltd (ASX: COL) dividend yield is now well under 4% (where it has spent most of its ASX life) at 3.4% today.

But what if I told you there was an ASX dividend share out there that today trades on a dividend yield well north of 5%. This passive income payer also tends to dole out full franking credits with its dividends, and pays those dividends every month too.

This is no unicorn. It is Plato Income Maximiser Ltd (ASX: PL8), a listed investment company (LIC) on the ASX that specialises in delivering a stream of fat, fully franked dividends to its shareholders 12 times a year.

Like most LICs, Plato owns its own portfolio of ASX shares, which it manages on behalf of its investors. AS you would suspect, this portfolio is selected based on each ASX dividend share's income potential and track record of paying income.

As of 31 January, some of this LIC's largest positions included ANZ Group Holdings Ltd (ASX: ANZ), Woodside Energy Group Ltd (ASX: WDS), Goodman Group (ASX: GMG) and Yancoal Australia Ltd (ASX: YAL).

So you can see where Plato's big yield comes from. But let's get into the numbers.

A monthly-paying, 5%-yielding ASX passive income share?

Over the past year, Plato Income Maximiser has paid out 12 dividends, each worth 0.55 cents per share. The latest of these was coincidentally paid out just today. That monthly paycheque of 0.55 cents per share adds up to an annual total of 6.6 cents per share in fully-franked passive income.

At the current share price of $1.28, that 6.6 cents gives Plato a trailing dividend yield of 5.17%.

If this income company keeps its payouts steady over the coming 12 months, it could mean that investors could potentially secure a 0.43% yield every month from this passive income payer.

Let's see whether this dividend stock can keep up its generous dividends for the rest of 2025.